KluwerArbitration

The Evidence of Corruption in Investment Arbitration

Document information

Olivier Caprasse; Maxime Tecqmenne

Publication(*) (**)

Journal of International
Arbitration

A great deal has been written over the years about the evidence of corruption ininternational arbitration. In that context, this article offers a timely analysis of some of themost contentious rules and principles applicable in relation to the evidence of corruption
allegations in investment arbitration. On the basis of an assessment of forty investment
awards dealing with corruption, it is demonstrated that it matters relatively little which
standard of evidence is applied by arbitral tribunals. The arbitral practice also reveals that,in recent years, arbitrators have come to rely more heavily on their discretion overevidentiary matters in order to contribute to the fight against corruption. This trend has
materialized not only in relation to the arbitrators’ growing reliance on their investigative
powers, but also their acceptance of more flexible means of evidence for the purpose ofdemonstrating the reality of corrupt practices.

TopicsInvestment Arbitration

Key words

Investment arbitration
Evidence of corruption
Standard of evidence
Means of evidencePower to raise corruption
matters sua sponte

Bibliographic
reference

1 INTRODUCTION

Olivier Caprasse andMaxime Tecqmenne, 'The
Evidence of Corruption in
Investment Arbitration', inMaxi Scherer (ed), Journalof International Arbitration,(© Kluwer Law
International; Kluwer Law
International 2022, Volume
39 Issue 4) pp. 519 - 548

It is a truism to say that corruption is – at least legally speaking (1) – almost universallycondemned. Over the past few decades, there has indeed been a growing international
consensus regarding the fight against corruption. (2) The prohibition against corruption
features in various anti-corruption international treaties and conventions such as theUnited Nations Convention Against Corruption (UNCAC), the Organization for Economic Cooperation and Development (OECD) Convention on Bribery of Foreign Public Officials in
P 520
International Business Transactions, and the Council of Europe Conventions on
corruption. (3) There is no denying that these international and national initiatives haveturned the spotlight onto the fight against transnational corruption in international law
and policy. That prohibition is also recognized – albeit to varying degrees (4) – in thevast majority of states. Countries such as the United States, France, England andGermany, to name but a few, have enacted laws and regulations with the aim ofcriminalizing corruption. As a consequence, there appears to be growing recognition thatthe prohibition of corruption belongs to transnational public policy. (5)In that context, it is rather unsurprising to observe that the number of allegations ofcorruption in investment arbitration has increased markedly over the past few years. No
less than thirty awards involving allegations of corruption have been rendered since 2010.
Such allegations may arise at different stages of the arbitral proceedings. They may be
invoked by the host state to deny the competence of the tribunal – as a bar either tojurisdiction or to the admissibility of the claim. (6) The use of this objection raises thornyquestions relating to the manner in which arbitral tribunal should deal with claims
involving corruption. Much has already been said and written, in particular, on whether
an arbitral tribunal may decide to deny access to international arbitration to an investor
whose investment is tainted by corruption even in the absence of an explicit ‘legality
requirement’ in the relevant Bilateral Investment Treaty (BIT). (7) In addition, theseP 521 allegations may also be invoked by the investor itself at the merits stage to allege aviolation by the host state of its international obligations under the relevant BIT. (8)When a claim involving corruption is brought forward, arbitrators – and indeed parties
alike – may have a hard time demonstrating that corruption has indeed occurred. In
practice, the true nature of corruption is often concealed behind seemingly legaltransactions, and the parties will make sure to leave no ‘incriminating evidence of theiractivities’. (9) As a consequence, it may be difficult to find straightforward evidence todemonstrate corrupt practices. (10) Even if such evidence exists, arbitral tribunals may
not always be able to obtain such evidence given that they enjoy rather limited
investigative powers in comparison with domestic courts, especially in relation to theirability to compel the production of relevant evidence and subpoena witnesses. (11) The
difficulty is further compounded by the relatively little amount of guidance offered bynational laws, arbitral rules, as well as international conventions in relation to the rules
and principles governing the evidence of corruption in international arbitration.
In that context, this article seeks to provide an overview of the arbitral jurisprudence onsome of the most salient evidentiary matters with respect to claims involving corruption.
For that purpose, an analysis of the arbitral jurisprudence dealing with corruption was
conducted. From the outset, it must be stressed that this analysis does not deal withcases in which corruption was not examined at any real length. There have been
instances where the arbitral tribunal dispensed with the issue of corruption, (12) andP 522 similarly, the parties themselves have sometimes dropped their claims of corruption
in the course of proceedings. (13) Beyond those cases, this article relies on an analysis of
forty awards to shed more light on the evidentiary principles governing corruption
claims. On the basis of that analysis, this article seeks to address the question of whether
arbitral tribunals are bound by a duty to raise and perhaps even investigate allegations

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of corruption of their own volition (section 2), before analysing the rules and principles
governing the standard and burden of evidence of corruption (section 3). The article thenmoves on to deal with the arbitral practice in relation to the assessment of the evidenceof corruption (section 4).

2 ARBITRAL TRIBUNAL’S POWER TO RAISE CORRUPTION MATTERS ON ITSOWN MOTION
Arbitral tribunals may sometimes have manifest grounds for suspecting that adispute – or the contract giving rise to that dispute – is tainted by an issue of public
policy even though the parties themselves have not raised that issue in theirsubmissions. It is generally accepted that the tribunal retains the power to investigate
and take initiatives to obtain further evidence of fact or law, (14) especially with respect
to issues that were dealt with by the parties. By contrast, it is a matter of great debate
whether and to what extent the arbitral tribunal may – or perhaps even should – beallowed to expand the dispute by raising sua sponte such issues of public interest beyond
the disputed questions submitted by the parties. Unfortunately, most investment
treaties and arbitral rules do not provide any guidance on that matter, and it has
accordingly generated considerable controversy in academic literature and arbitraljurisprudence.
At the heart of that debate there features a paradox – or dilemma – between two
overarching principles of international arbitration. On the one hand, the principle ofparty autonomy militates in favour of a laissez-faire attitude on the part of arbitrators. On
P 523 the other hand, it must be noted that the enforcement or recognition of an award may
be refused if it is deemed to be contrary to the public policy of the country in which
recognition or enforcement is sought. (15) Several arbitral awards have effectively been
annulled or set aside on the ground that they were not in compliance with public policy.
(16) Similar arguments have been advanced successfully before the French Court ofAppeal in the context of requests to set aside arbitral awards for violation of theprinciples of international public policy, including matters involving fraud, money
laundering or corruption. (17) It has been suggested, in that respect, that public policy
considerations support a more proactive approach from the tribunal with respect tomatters of public interest, (18) subject to compliance with the parties’ due process
guarantees and, in particular, their right to be heard and right of equal treatment. For
that reason, some commentators have posited that arbitral tribunals are bound by a duty
to address and perhaps even investigate salient issues of public interest provided thatthey belong to mandatory rules or transnational public policy – such as matters involving
corruption, money laundering, and embezzlement. (19)The same reasoning may admittedly not so readily apply in relation to arbitration
proceedings carried out under the auspices of the Convention on the Settlement of
Investment Disputes between States and Nationals of Other States (‘the International
Centre for Settlement of Investment Disputes or ICSID Convention’). One of the mostpeculiar features of the ICSID system is that public policy does not feature amongst the
grounds for annulment described in Article 52 of that Convention. This means that theparties cannot challenge the award on that ground. As a consequence, it falls upon thearbitrators themselves to deal with any issues of public interest that may arise in thecourse of proceedings, or else such issues will not be addressed at all. In other words,
there is no way for the parties to initiate subsequent proceedings to redress that defect.
P 524 In those circumstances, the arbitral tribunal is (formally speaking) under no obligation
to raise issues of public interest on its own motion. It is sometimes suggested, however,that the public dimension of investment arbitration ‘militate[s] towards requiring
arbitrators to make use of independent fact-finding powers’ in those circumstances. (20)Even in the context of ICSID arbitration proceedings, the arbitral tribunal should thus
strive to make use of its investigative powers – by requesting the production of specificevidence, or ordering the attendance of a third-party witness – in order to shed light on
those public policy issues even if they were not addressed by the parties in theirsubmissions.
If these are the terms of the debate as to the powers of arbitrators in investment
arbitration in general, some commentators also consider that there is growing
acceptance in relation to the arbitral tribunal’s authority to address and even perhaps
investigate allegations of corruption on its own initiative. (21) Although the practice ofarbitral tribunals in that respect has traditionally been rather inconsistent, (22) recent
arbitral awards seem to indicate that at least some arbitrators are willing to make use of
their fact-finding powers to investigate potential suspicions of corruption arising during
the arbitration. (23)One of the most striking features of Metal-Tech v. Uzbekistan is that the tribunal decided
to rely on its ex officio investigative powers described in Article 43 of the ICSID
Convention in order to cast some light on suspicions of corruption that arose in the courseof the arbitration. During the hearing on jurisdiction, the tribunal became aware of threeimportant elements raising suspicions of corruption. In the first place, the claimant’s CEO
admitted that the consulting agreements concluded by Metal-Tech and three of its
consultants were already running before the investment was made. Prior to that hearing,
the evidence on record indicated that these agreements had only been concluded a few

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years after the making of the investment. In the second place, it was also revealed thatthe consultants did not perform the services described in the consulting agreements.
Instead, they were employed to perform ill-defined ‘lobbying activities’. Moresurprisingly still, it was also revealed that they had been paid in the strikingly large
amount of approximatively USD 4 million.
The tribunal observed that the payments made by Metal-Tech were disproportionate incomparison with the overall value of the transaction because they ‘exceeded its initial
P 525 cash contribution … and amounted to nearly 20% of the entire project costs’. (24)Viewed together, these elements raised reasonable suspicions about the true nature ofthese transactions. Although none of the parties had raised allegations of corruption, thetribunal therefore decided to delve further into the nature and purpose of the services
provided by Metal-Tech’s consultants. For that purpose, it made use of its fact-finding
powers and requested the claimant to produce further evidence demonstrating that
actual and effective services had been performed ‘for legitimate purposes in return for
those payments’. (25) In the light of Metal-Tech’s failure to adduce evidence to that
effect, and despite repeated attempts by the tribunal to obtain such evidence, thetribunal subsequently inferred that ‘no services, or at least no legitimate services at thetime of the establishment of the Claimant’s investment, were in fact performed’. (26)The tribunal’s approach in Metal-Tech is consonant with a widespread view in academic
literature that the tribunal should be able to raise – and perhaps even investigate (27)– issues involving corruption of its own volition. (28) It also falls in line with the approach
adopted recently by the Singapore International Commercial Court in Lao Holdings NV
and Sanum Investments Ltd v. Government of the Lao People’s Democratic Republic. (29) In
its decision, the Court upheld two awards that had dismissed the claims put forward by
the claimants on the basis of findings of corruption. The claimants subsequently filed an
application to set aside these two awards on the ground that the tribunals exceeded thescope of the parties’ submission by admitting new elements of evidence. It is worth
stressing that the parties initially settled the dispute and decided that the record in thearbitrations would remain frozen even if the claims were revived. In that perspective, theparties reached a settlement by which they agreed that no new claims, evidence, or
reliefs would be accepted. After the arbitration proceedings were resumed, however, thearbitral tribunals accepted the respondent’s request to introduce decisive new elements
to support its allegations of corruption.
In its decision, the Singapore Court concurred with the tribunals’ approach. It opined thatthe tribunal was bound by a ‘public duty’ to address corruption ‘not only where [it] has todeal with allegations of corruption in the dispute between the parties, but also where theevidence in the case indicates possible corruption’. For that reason, the Court concluded
that arbitral tribunals ‘have a pro-active role and cannot simply ignore evidence ofP 526 corruption’. This meant, in particular, that ‘no agreement between the parties canprevent the tribunal from reviewing and, where appropriate, admit[ting]’ new elements ofevidence demonstrating corrupt practices. (30) It is suggested here that this approach isindeed warranted considering the risk of annulment or non-enforceability affecting anaward rendered in violation of the prohibition of corruption. It must nevertheless be
stressed that the tribunal’s initiative should only be undertaken if prima facie evidenceor red flags arise leading it to suspect that the transaction might be affected by corrupt
practices, (31) as otherwise the award may be challenged on the ground that the tribunal
has exceeded its mandate. (32)
Ultimately, though, it falls upon each tribunal to assess the elements adduced by theparties on a case-by-case basis, and to decide whether to carry out further investigation.
In the subsequent case of Infinito Gold v. Costa Rica, (33) for instance, it may be suggested
that the arbitral tribunal’s somewhat more cautious approach to the use of its
investigative powers was justified by reference to its assessment of the cogency of theevidence pertaining to corruption. In that case, the claimant, Industrias Infinito, had
obtained an exploitation concession for the extraction, processing, and sale of minerals
from the Las Crucitas gold deposit, an area located in Costa Rica. That concession waslater annulled by the Constitutional Court on the grounds that it violated the right to ahealthy and ecologically balanced environment. That judgment was subsequently
repealed by then-President Óscar Arias. The later decided to grant an exploitation
concession to the claimant by converting the previously annulled concession into a validone.
In the subsequent arbitration proceedings launched by the claimant, the Costa Rican
government alleged that the former President’s decision was affected by corruption. It
was submitted, in particular, that he had received a donation from the claimant’s
shareholder for the purpose of securing the award of the concession. In support of that
allegation, the host state relied on an ongoing investigation against former PresidentÓscar Arias and other state officials in relation to the award of the concession. In thecourse of proceedings, the respondent withdrew its claim following the decision by a
Costa Rican criminal court to discontinue the investigations on the grounds that theP 527 charges proffered against the former President were time-barred.
In spite of the respondent’s withdrawal of its claim, the tribunal decided to addressthese corruption allegations ex officio. According to the tribunal, ‘corruption
allegations … raise an issue of international public policy’ and, as such, they must be3© 2022 Kluwer Law International, a Wolters Kluwer Company. All rights reserved.

addressed by the tribunal even if the parties decided not to rely upon them in their own
pleadings. (34) At first glance, the arbitral tribunal’s pronouncements may therefore beseen as confirming the trend ushered in by Metal-Tech. Ultimately, though, the tribunal’s
approach was rather more cautious in comparison with that in Metal-Tech. Morespecifically, the tribunal refrained from requesting further evidence on the allegations.
Instead, it merely relied on the evidence adduced by the parties at that stage. The
tribunal subsequently concluded that the evidence produced by the parties wasinsufficient to demonstrate corruption. In support of that conclusion, the tribunal
stressed, in the first place, that the investigation had been discontinued and that therewas ‘no indication that the charges against President Arias [could] proceed’. (35) On theface of it, that argument is not entirely convincing. Although there is no denying thatthese investigations were discontinued, it appears that that decision was made only on
the basis of procedural grounds. In other words, the decision was adopted without
prejudice to the merits of that investigation. The tribunal nevertheless added, in thesecond place, that there was no evidence to support the conclusion that the former
President had received a donation from one of the claimant’s shareholders. In reaching
this conclusion, the tribunal was satisfied that it had ‘discharged its ex officio duty inmatters of international public policy’. (36)
In the light of Infinito Gold v. Costa Rica, it can be suggested that the existence of a duty
to raise ex officio allegations of corruption is commonly accepted in arbitral practice. At
the same time, however, that duty does not necessarily encompass a duty to investigate
such allegations. That decision in that case may indeed be seen as an indication that
arbitral tribunals will only consider making use of their investigative powers provided
that there is specific prima facie evidence raising suspicions of corruption. In thatperspective, the tribunal’s somewhat cautious approach may have been justified by therather scarce evidence provided by the parties in relation to the allegation of corruption.
It is rather surprising, however, that the tribunal did not engage further with these issues,
especially considering the fact that an official investigation was launched against theformer President in relation to allegations of corruption pertaining to the claimant’s
investment. In line with the tribunal’s approach in Metal-Tech, it may be suggested thatsuch investigations constitute precisely the type of evidence required to give rise to a
P 528 reasonable suspicion that an investment is tainted by corruption. In choosing toinvestigate, arbitrators should also take into consideration the inherent difficulty todemonstrate corruption with certainty. (37) If the tribunal decides to conduct further
investigation of its own motion, it must further be stressed that it must comply with theparties’ right to be heard. This means, in particular, that the parties should be informedof the tribunal’s concerns and offered the time and opportunity to share their views on
the matter. (38)3 BURDEN AND STANDARD OF PROOF OF CORRUPTION IN INVESTMENT
ARBITRATION
When it is called upon to decide on the parties’ claims, the arbitral tribunal must identify
the rules applicable to evidentiary matters such as the burden and standard of proof.
The rules applicable to those matters may indeed influence the outcome of allegations ofcorruption. The rules on the allocation of the burden of proof aim to determine the party
who bears the burden of adducing evidence in support of its allegations. (39) That party
will accordingly lose if the relevant assertion remains unproven. As to the rules on theprevailing standard of proof, they define the level or degree of confidence required toconclude that the fact of corruption is demonstrated. (40) As such, these rules determine
whether the evidence adduced by each party is sufficient to support a finding ofcorruption. The identification of the laws and regulations applicable to the burden andstandard of proof may therefore have a bearing on the outcome of allegations ofcorruption.
Whilst there is no denying that most national and international provisions on the burdenof proof contain similar – if not identical – solutions, the same conclusion does notprevail in relation to the standard of proof. Diverging approaches towards the standard of
proof exist depending on the applicable national laws and regulations. It is perhaps fairto acknowledge at this stage that, in contrast to common law systems, most civil law
systems do not necessarily articulate the very concept of ‘standard of evidence’ in a clear
and explicit fashion. (41) This is especially the case in civil and commercial matters. (42)That does not mean, however, that this concept is simply non-existent in those legal
P 529 orders. Just because the terminology ‘standard of evidence’ is not employed in an
explicit manner, this does not necessarily mean that the idea underlying this concept is
simply absent in those countries. As aptly pointed out by Patrick Kinsch, determining theappropriate standard or ‘degree’ of evidence is also a matter of concern in continental
legal systems. (43) In any event, we shall see that even though the approaches adopted incommon and civil law jurisdictions seem to diverge considerably, they may notnecessarily lead to diverging outcomes. One of the most recurring questions in that
respect is whether the rules on the burden and the standard of proof should bedetermined in accordance with the substantive or procedural legal rules governing theinvestment arbitration. (44)Against that background, this section is structured as follows. After dealing with the4© 2022 Kluwer Law International, a Wolters Kluwer Company. All rights reserved.

question of which law governs the standard and burden of proof (3.1), it delves into anassessment of the burden and standard of proof applied in practice by arbitral tribunals
when they deal with allegations of corruption. It is demonstrated, in particular, that therule actori incumbit probatio is universally recognized and applied by arbitral tribunals(3.2), whereas the requisite standard of evidence gives rise to considerable debates inlegal scholarship and arbitral practice (3.3).

3.1 Law applicable to the burden and standard of proof
The question of which law applies to the burden and standard of proof has generated
considerable controversy in arbitral jurisprudence and legal scholarship. It is worth
mentioning from the outset that there are, broadly speaking, two approaches to theidentification of the rules applicable to the arbitration. The first approach, which may
aptly be qualified as the ‘conflict of law approach’, dictates that arbitrators should apply
the relevant conflict of law provisions to determine the rules applicable to thearbitration. In turn, the relevant conflict of law provision must be identified with due
regard to the applicable investment treaty or, in the absence of specific provisions in thetreaty, national legal provisions. While the country of the seat traditionally serves as areference in that context, that does not hold true in relation to ICSID arbitration
proceedings which are internationalized and, hence, do not have a seat. When it comes,
P 530 in particular, to the substantive rules governing the merits of the dispute, Article 42(1)of the ICSID Convention specifies that they must be identified by reference to the law of
the host state, as well as rules of international law. Besides the traditional conflict of law
approach, a second approach, dubbed the ‘voie directe approach’, is also commonly
applied by arbitrators. That approach is explicitly endorsed by some arbitration rules.
(45) Based on that approach, it falls upon the arbitral tribunal to determine directly therules applicable to the arbitration without any reference to the conflict of law provisions
originating from a specific legal order.
Against that background, most commentators seem to consider that the rules on burden
and standard of proof belong to the substantive rules governing the merits. (46) In
practice, it would nevertheless seem that arbitral tribunals have differed on the questionof whether these matters belong to the procedural or substantive rules governing thearbitration. The uncertainty resulting from those diverging approaches is further
compounded by the fact that some tribunals may even sometimes establish a distinction
between the rules on the burden of proof and those pertaining to the standard of proof.
That approach was most notably adopted by the tribunal in Jan Oostergetel. According to
the tribunal, ‘[w]hile the general principle actori incumbit probatio pertains to theprocedure … the rules establishing presumptions or shifting the burden of proof undercertain circumstances … are generally deemed to be part of the lex causae’. (47) This
statement offers an illustration of the approach according to which the burden of proof
must be determined by reference to the procedural rules governing the arbitration, while
the standard of proof must be identified in accordance with the law chosen by theparties to govern the merits of the dispute.
It must also be pointed out that most arbitral tribunals have remained somewhat
oblivious to the issue of identifying the relevant laws and regulations applicable to theseevidentiary matters. One of the reasons justifying that approach may simply arise fromthe fact that in some cases the parties themselves did not specifically address thatmatter, but preferred instead to rely upon authoritative sources such as, for instance,
P 531 previous arbitral awards or academic legal writings. (48) In addition, as far as theburden of proof is concerned, that approach may be warranted considering the broadconsensus existing across national jurisdictions about the principle actori incumbit
probatio. (49) Beyond this, that approach may also be explained by reference to therelatively small amount of guidance proffered by national laws, arbitration rules andinternational customary law with respect to these evidentiary matters. (50) In the
majority of cases, the applicable substantive law – which is usually the relevant BIT (51)– does not commonly include detailed guidance on evidentiary matters. In the samevein, most arbitration rules, customary international law and applicable procedural laws
do not offer much guidance on such matters. In particular, they remain silent on theapplicable burden and standard of proof. The only prevailing rule of evidence is the freeappreciation of evidence by the tribunal. (52) The principle of free evaluation of evidence
entails that arbitral tribunals are free to determine the weight to be attached to aparticular item of evidence, and remain sovereign when it comes to the assessment of
the admissibility of such pieces of evidence. (53) It must nevertheless be stressed that
this principle does not offer ‘any positive standard of proof’. (54) As a consequence, thearbitral tribunal is not bound by specific rules of evidence when it comes to theidentification of the burden and standard of proof applicable in each case underconsideration. It would therefore seem that the prevailing burden and standard of proof
may be determined irrespective of the laws and regulations governing the arbitration.
That approach is illustrated by the reasoning exhibited in Gavrilovic v. Croatia. In thatcase, the arbitral tribunal considered that it was not bound by any specific rule orevidence and could determine the burden of proof irrespective of the solutions provided
in different jurisdictions. The tribunal initially observed that ‘the ICSID Convention, theP 532 ICSID Arbitration Rules and the BIT do not provide guidance for determining whichparty bears the burden of proof’. For that reason, the tribunal subsequently went on to5© 2022 Kluwer Law International, a Wolters Kluwer Company. All rights reserved.

state that:in the absence of mandatory rules as to how a tribunal should judge theprobative value of evidence put before it, therefore, the tribunal considers it
appropriate to apply the general approach taken in international disputesettlement which is not characterized by formal rules of evidence. (55)
It subsequently relied upon an analysis of the arbitral jurisprudence on that matter to
identify the principle actori incumbit probatio as being applicable in the proceedings.

3.2 Burden of proof
The Latin maxim actori incumbit probatio is almost universally recognized as being
applicable in investment arbitration and, more generally, in international arbitration.
(56) Considering arbitral tribunals’ wide acceptance of that principle, it is rather
surprising to observe that it has not been enshrined explicitly in most sets of arbitration
rules. That principle features most notably in the United Nations Commission on
International Trade Law (UNCITRAL) Arbitration Rules, (57) as well as the Iran-UnitedStates Claims Tribunal Rules of Procedure. (58) It is also recognized and applied in most,
if not all, legal systems. (59) It follows that the actori incumbit probatio rule may bedeemed to constitute a general principle of law pursuant to Article 38(c) of the Statute of
the International Court of Justice. (60) Some commentators even believe that it belongs
to the lex mercatoria. (61) Based on that principle, each party must adduce evidence toP 533 support its own assertions of facts.
That principle has repeatedly been reaffirmed in relation to allegations of corruption. It
follows that the party who alleges the presence of corruption must produce evidence todemonstrate that it has indeed occurred. (62) The question frequently arises as towhether the burden of proof may be shifted in circumstances – such as those involving
fraud, money laundering or corruption – where a party alleging a fact may have tograpple with serious difficulties in demonstrating that it has occurred. It would appear
that arbitral tribunals have generally been reluctant to accept to shift the burden of
proof in such circumstances. (63) It seems, in particular, that no investment tribunal has
ever agreed to shift that burden of proof thus far.

3.3 Standard of proof
3.3[a] General Considerations on the Standard of Proof in Investment Arbitration
Whilst the principle actori incumbit probatio is uniformly applied by arbitral tribunals,
there appear to be varying approaches in relation to the standard of proof applicable ininvestment arbitration. It is often suggested that the most commonly applied standard of
proof is the common law standard of ‘balance of probabilities’ or ‘preponderance ofevidence’. (64) At the same time, though, this standard is not applied uniformly byarbitral tribunals. (65) As we shall see, some tribunals have also determined a heightened
standard of proof in circumstances where serious allegations involving wrongdoing suchas fraud, money laundering or corruption are made. (66) Arbitral tribunals have also
regularly refrained altogether from articulating the appropriate standard. (67) TheseP 534 varying approaches towards the applicable standard of proof may be partly related tothe broad discretion enjoyed by arbitral tribunals in relation to evidentiary matters. As
we have seen, most institutional rules of arbitration remain silent on the standard of
proof to be applied by arbitral tribunals. Quite unsurprisingly, arbitrators therefore
retain the power to set the appropriate standard in the light of the circumstances of eachcase, (68) subject to compliance with due process requirements. (69)
In practice, the arbitrators’ choice of standard of proof may sometimes be influenced by
the varying standards of proof emanating from specific legal orders. (70) Most arbitral
tribunals do not explicitly refer to a specific legal order when it comes to defining theprevailing standard of proof, preferring instead to rely upon earlier investment
arbitration awards in order to support their own findings on the applicable standard. (71)They may also take into account the jurisprudence from international courts andtribunals for that purpose. For instance, the arbitral tribunal in Sanayi v. Pakistan relied
upon a jurisprudential precedent emanating from the International Court of Justice tosupport its findings on the relevant standard of proof. (72)
But the influence drawn from specific legal orders may be more explicit. It is not unusual
for arbitral tribunals to expound – albeit sometimes very briefly – on the evidentiary
principles applicable in different legal orders to ground their decision as to the standardof proof applicable in a given case. (73) The rules on evidentiary matters may differ to acertain extent depending on the applicable national laws and regulations. Morespecifically, the rules on standard of proof may vary considerably between civil law andcommon law traditions. In the same vein, there may also be differing rules on standard of
proof within a specific national legal order depending on the nature and consequence ofa claim. In this respect, we shall see that a difficulty arises from the nature of illegal
P 535 activities such as corruption. As the latter constitutes a criminal offence, somearbitrators insist that it should be subject to a heightened level of proof even in thecontext of international arbitration. At the same time, however, that position is contested
by other arbitral tribunals on the ground that the arbitration procedure does not purport

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to determine the criminal law implications, but rather the civil consequences resulting
from the alleged corrupt activities.
In common law countries such as England and the United States, the applicable standardof proof depends on the nature of the claim. (74) The standard applicable in relation tocivil claims is the ‘preponderance of evidence’. That standard is otherwise known in the
United States as the ‘balance of probabilities’. It follows that a fact will be considered as
established if the probability that it has indeed occurred exceeds 50%. (75) In contrast,
the level of proof required to establish that a fact has occurred in the event that a claim
involves important individual rights and interests must reach the greater threshold of‘clear and convincing evidence’. That standard entails that the judge or arbitrator mustbe satisfied that the allegation is ‘significantly more likely to be true than not true’. (76)The applicable standard is even higher in relation to criminal claims. In thosecircumstances, the judge must be convinced that the alleged event has occurred ‘beyonda reasonable doubt’. (77)
As we have seen, most civil law jurisdictions stand in stark contrast with comparison tocommon law systems because they do not offer much guidance on the standard ofevidence. The standard applicable with respect to all claims – including both civil andcriminal claims – is the ‘inner conviction’ test. The precise meaning of that test
nevertheless remains somewhat elusive. Unfortunately, it does not ‘indicate the degree
or quantum of evidence’ required to consider a fact as proven. (78) As already mentioned,
that does not necessarily mean, however, that the concept of ‘standard of proof’ is notrecognized to some extent by civil law systems. In civil law countries such as France,
Belgium and Switzerland, the requisite standard of evidence is often described as‘certainty’. (79) More specifically, the degree of certainty required in relation to criminal
law matters reaches the level of proof ‘beyond any reasonable doubt’ or ‘unsurmountable
P 536 doubt’. (80) In contrast, the allegation will be considered as demonstrated in civil
cases if the probability that it has indeed occurred reaches the threshold of ‘certainty’ or,at the very least, ‘reasonable certainty’. (81)
At a first glance, the difference in terminology would suggest that the civil law standard of‘certainty’ is different from the common law standard of ‘balance of probabilities’. Unlike
the common law standard of evidence, which is characterized by an objective, if notmathematical, approach, the civil law approach towards the standard of evidence relies
more heavily on the subjective dimension of the evaluation of the evidence presented by
the parties. (82) At the same time, however, it is widely assumed that the application of
the relevant standard does not necessarily lead to a different outcome. (83) What mattersmost, at the end of the day, is that arbitrators and judges should ‘evaluate the evidence
produced and be convinced that the evidence is more likely than not’. (84)3.3[b] Standard of Proof of Corruption in Investment Arbitration
It can be inferred from an analysis of the arbitral jurisprudence on allegations ofcorruption that arbitral tribunals have differed in their approaches towards the standardof proof required to demonstrate the fact of corruption. Most arbitral tribunals failentirely to consider the appropriate standard of proof. Amongst the forty awards
analysed in the context of this article, twenty-two do not feature a decision on theapplicable standard of proof in relation to these allegations. The tribunal in Niko
Resources v. Bapex even went as far as to consider that the question of the appropriate
standard of proof did not provide much assistance to the tribunal in the assessment of
the evidence of corruption. (85) In the same vein, Emmanuel Gaillard observed that
discussion of the adequate standard of proof is to ‘a large extent academic’ since arbitralP 537 tribunals enjoy great leeway when it comes to the appreciation of evidence. (86)Arbitral tribunals’ apparent lack of engagement with the standard of proof mainly occurs
in relation to one specific situation. In particular, it seems that arbitral tribunals usuallyrefrain from setting a specific standard of evidence in circumstances where the evidence
is clearly lacking because the party alleging corruption has failed to substantiate its
allegations. One of the most common features of these awards is that the party alleging
corruption relied on mere insinuations or general allegations of corruption, but failed toprovide specific and relevant evidence of the alleged corrupt practices. (87) In
Bridgestone v. Panama, (88) for instance, the claimants submitted that the Supreme Court
judgment adopted in a case involving them was affected by corrupt practices. In supportof that contention, they mentioned several elements allegedly supporting a finding ofcorruption. Amongst those featured several non-governmental organizations’ reports
demonstrating the widespread nature of corruption in the judiciary of Panama, as well ascomplaints of corruption filed against the judges involved in the drafting of their
judgment. These elements were relied upon by the claimants in order to support theargument that the errors in substance deriving from the judgment could only be
explained by reference to corruption. The tribunal nevertheless considered that theseelements constituted mere insinuations of corruption that did not relate specifically tothe claim of corruption brought forward by the claimant. They were therefore deemed to
be insufficient to conclude that corruption had indeed occurred.
The tribunal in ECE Projektmanagement v. Czech Republic (89) was also confronted withsimilar arguments involving general allegations of corruption. In the case underconsideration, the claimant alleged that the respondent state had breached the fair and7© 2022 Kluwer Law International, a Wolters Kluwer Company. All rights reserved.

equitable treatment (FET) standard owing to serious irregularities pertaining to theprocess leading up to the award of building permits for the construction of shopping
centres – which the claimant subsequently abandoned. In that context, the claimant
P 538
alleged that one of its main competitors paid bribes to the state authorities with aview to delay the award of its own permit. In that relation, the claimant relied upongeneral evidence deriving from NGOs’ reports demonstrating the systemic nature ofcorruption in the Czech Republic. It was submitted that these elements, in combination
with serious irregularities affecting the building permit process, supported theconclusion that the process had been affected by corrupt practices. The tribunal was notconvinced. Although it was willing to ‘connect the dots’ offered by the claimant, thetribunal found that there was no evidence of any specific act of corruption. It insisted, inparticular, on the need to remain:
vigilant against blanket condemnatory allegations which can have theappearance of an attempt to ‘poison the well’ in the hope of making up for alack of direct proof. Reference to other instances of alleged corruption may
prove that corruption exists in the state, but it does little to advance theargument that corruption existed in the specific events giving rise to theclaim. (90)When it has been addressed explicitly by international arbitral tribunals, the question of
the appropriate standard of proof in relation to allegations of corruption has given rise tocontroversy. From the outset, it must be stressed that most arbitral tribunals have paid
little to no attention to the preliminary step of identifying the law applicable to the issueof the standard of proof. (91) It would seem, in particular, that arbitral case law only
features scarce reference to the solutions applied in different national jurisdictions. (92)
In Croatia v. Mol, for instance, the tribunal duly considered the respondent’s argumentthat the standard of evidence should be the standard of ‘reasonable certainty’ inaccordance with the substantive law applicable to the dispute (i.e., Croatian law).
Ultimately, though, the tribunal grounded its decision on the basis of two arbitralprecedents dealing with corruption. (93) In the same vein, most arbitral tribunals flesh
out the relevant standard of proof by reference to previous arbitral awards, (94) while
several tribunals did not even provide support for their findings based on any
P 539 authoritative legal reference. (95) That approach seems to indicate that arbitral
tribunals usually consider that they are not bound by specific rules of evidence when it
comes to the identification of the relevant standard of evidence.
The analysis conducted in the context of this article also reveals that there is nouniversally accepted standard of proof with respect to such allegations. It is sometimes
suggested that claims involving serious wrongdoings such as fraud, bribery, or moregenerally any impropriety pertaining to international public policy should be dealt within accordance with a high standard of proof. (96) In those circumstances, the chosen
standard may vary across a spectrum of possibilities ranging from ‘proof beyond doubt’(97) to the ‘irrefutable evidence’ standard (98) ; although, in most instances, it is thestandard of ‘clear and convincing evidence’ that prevails. (99) Oft-repeated in support ofthat approach is the argument that the gravity of such allegations warrants a different
approach from that applied under the rules and principles governing the evidence forother claims. (100) Whether a claim of corruption is successful or not may indeed have asignificant bearing on the outcome of the arbitration proceedings, especially given that afinding of corruption may constitute a bar to the competence of the tribunal. Further
support for this approach may also be drawn from an analysis of the evidentiary rules
applicable in some national jurisdictions. It has been stated above that the standard of
proof applicable in some jurisdictions may depend on the nature of the claim. In
common law jurisdictions, for instance, the prevailing standard of proof is that of ‘proof
beyond reasonable doubt’ in respect of criminal law claims. Given that corruption isconsidered a criminal offence in most legal systems, it is sometimes suggested that thestandard applicable to allegations of corruption should be raised even in the context of
P 540 international arbitration.
That approach has gained some traction in legal scholarship and, more importantly, inarbitral practice. According to the tribunal in Karkey v. Pakistan, there is a ‘large
consensus among international tribunals regarding the need for a high standard of proof
of corruption’. (101) Upon closer analysis of the arbitral jurisprudence dealing withcorruption, it is nevertheless suggested here that the tribunal’s pronouncement was asignificant exaggeration. There is no denying that the majority of tribunals consider thatthe applicable standard of proof should be greater – or ‘heightened’ – in relation toallegations of corruption. More specifically, the analysis reveals that ten out of theeighteen awards dealing explicitly with the issue of standard of evidence havearticulated a higher standard compared to the traditional standard of ‘balance of
probabilities’. (102) However, a significant chunk of the arbitral jurisprudence – eight
awards – considered that the standard of proof applicable to civil matters should beapplied in relation to claims of corruption. In recent years, it would seem that arbitral
tribunals have increasingly referred to the civil standards of ‘balance of probabilities’,(103) ‘preponderance of evidence’ (104) or ‘reasonable certainty’. (105) As we shall see,this development goes hand in hand with a discernible trend in arbitral jurisprudence
towards acceptance of more flexible forms of evidence to demonstrate illegal practices.

8© 2022 Kluwer Law International, a Wolters Kluwer Company. All rights reserved.

(106)
By contrast to the heightened approach, this approach focuses instead on the inherent
difficulty of proving corruption. Allegations of corruption are notoriously difficult todemonstrate with absolute certainty for various reasons. That difficulty may arise fromthe absence of direct evidence of the corrupt practice, especially given the fact that theP 541 true nature of corruption is often concealed behind seemingly legal transactions. But it
may also result from the rather limited investigative powers enjoyed by arbitrators. Quite
unfortunately, arbitral tribunals lack the power to ‘seize documents, compel theattendance of a party’s witness or force relevant third parties to participate inproceedings’. (107) Without the possible involvement of national judges in the collectionof evidence explicitly provided for by some national laws and arbitral rules, (108) they
may therefore be ill-equipped to gather the requisite amount of evidence.
The partial award rendered in Chevron Corp. v. Ecuador is worth mentioning here. Aninteresting feature of that decision is that the allegedly bribed individual did not attend
the hearing and accordingly could not defend himself against the allegations made by
the claimants. In the course of proceedings, the tribunal repeatedly expressed its wish tohear that individual’s testimony. Following several unsuccessful attempts by the
respondent state to invite the individual to participate in the hearing, the tribunal itself
decided to issue a procedural order by which it invited the witness to attend the hearing.
Unfortunately, the initiative taken by the tribunal was also unsuccessful. In that respect,that case provides an illustration of arbitral tribunals’ lack of investigative powers in
relation to suspicions of corruption. Whilst the tribunal sought to secure the presence ofthe main witness at the hearing, the fact remains that – as the tribunal duly noted – ‘it
was [that witness’] right to choose not to’ testify. (109)Considering the difficulty of demonstrating corruption, some commentators opine that
arbitrators should exercise the procedural flexibility which they derive from theirmandate in order to provide the parties with a reasonable opportunity to adduce
evidence that it has indeed occurred. (110) More specifically, the arbitral tribunal should
not necessarily opt for a higher standard of evidence, but instead for the more flexible‘balance of probabilities’ standard even in instances involving corruption. (111) Some
commentators have expressed doubts as to whether it is relevant to establish aheightened standard of proof by reference to considerations emanating from domestic
criminal laws and regulations. (112) In contrast to domestic criminal courts, international
arbitrators are not called upon to impose criminal sanctions. Rather, they are entrustedwith the task of determining the civil consequences resulting from allegations of
P 542 corruption in relation to the dispute submitted to investment arbitration proceedings.

4 ARBITRAL APPROACH TO THE ASSESSMENT OF EVIDENCE OF CORRUPTIONIN INVESTMENT ARBITRATION
The implications resulting from the choice of a specific standard of evidence are difficult
to appreciate in practice. It has been suggested that the choice of a heightened standardof proof ‘has had a direct impact on case law’ given that ‘every tribunal in which a higher
standard was employed has … resulted in tribunals being unable to positively rule that
corruption did indeed occur’. (113) That statement may still hold true today. There may
indeed be cases in which the standard of proof has a direct impact on the outcome of thearbitration proceedings. (114) In particular, it is worth mentioning here the awards
rendered in Sanum Investments v. Laos and Lao Holdings v. Laos. (115) In those cases, theoutcome of the claim of corruption raised by the host state was directly determined by
the applicable standard of proof. Although the tribunal concluded that the allegations ofcorruption were deemed as established on the basis of the ‘balance of probabilities’
standard, it nevertheless concluded that these allegations did not meet the requisite
standard of ‘clear and convincing evidence’ in the light of the government’s failure to
identify any bribe taker. The tribunal stressed, in particular, that ‘the government’s
failure to track down bribe-takers or to provide a convincing explanation of its efforts(even if on occasion unsuccessful) to do so, weighs against the government’s case’. (116) In
spite of that conclusion, the tribunal subsequently considered that ‘its conclusion that
corruption of government officials was established to the “lower standard ofprobabilities” [was] relevant to the issue of the claimants’ good faith’. (117) At the merits
stage, the tribunal rejected the investor’s claims for expropriation. It also added that, inany event, these claims should be dismissed as the claimants ‘exhibited manifest bad
faith in various efforts not only to manipulate the Government to advance their gambling
initiatives but [also] to manipulate the arbitration process itself’. (118) It remains
somewhat unclear, however, whether the tribunal would have reached a similar
conclusion if the material claims brought forward by the investor had prevailed. (119)In the light of the tribunal’s decision in Sanum Investments, it would appear that theon theoutcome of corruption allegations. At the same time, however, the present study reveals
that even when arbitral tribunals have opted for the lesser standard of ‘balance of
probabilities’ or ‘preponderance evidence’, it has rarely led to a positive finding ofcorruption. The analysis conducted in the context of this article reveals that, in the vast
majority of cases, claims of corruption have been unsuccessful. In contrast, it indicatesthat only four awards have led to positive findings of corruption. (120) Perhaps somewhat

P 543 tribunal’s choice of standard of evidence may sometimes have a direct impact

9© 2022 Kluwer Law International, a Wolters Kluwer Company. All rights reserved.

surprisingly, three of these four awards did not include any finding as to the standard ofevidence to be applied in relation to these allegations. It is also worth stressing in that
respect that in Metal-Tech v. Uzbekistan, the tribunal’s findings with respect to theappropriate standard of proof did not have a significant bearing on the outcome of thecase. In that case, the evidence on record was particularly incriminating and included, inparticular, a witness statement proffered by the claimant’s CEO admitting that
substantial payments had been made to several intermediaries for no legitimate reason.
In the light of this evidence, the tribunal insisted that:[w]hile the debate about standards of proof and presumptions is aninteresting one … the present factual matrix does not require the tribunal toresort to presumptions or rules of burden of proof where the evidence of thepayments came from the claimant and the tribunal itself sought further
evidence of the nature and purpose of such payments. (121)
The foregoing considerations suggest that it matters relatively little which standard of
proof applies in relation to allegations of corruption. What matters most, at the end of
the day, is the tribunal’s approach to the assessment of the evidence. This explains why
much of the debate in recent years has focused on the means of evidence available tothe parties in order to demonstrate the fact of corruption. Because corrupt practices are
inherently difficult to demonstrate, it seems more widely accepted that they may beestablished through indirect or circumstantial evidence (‘faisceau d’indices’). That
approach has been used increasingly by arbitral tribunals. It has also been accepted by
P 544 national courts dealing with requests to set aside international arbitral awards. (122)
Following that approach, a party can discharge its evidentiary burden by demonstrating‘a sufficient number of indicators of corruption, or the so-called “red flags”’. (123) Taken
on its own, each red flag would not suffice to conclude that corruption has occurred.
Viewed together, however, these red flags may be sufficient to establish the fact of
corruption. (124) It therefore falls to arbitral tribunals to ‘connect the dots’ of theindividual items of evidence adduced by the parties to determine whether corruption
has indeed occurred. This approach was described in Methanex as follows:
Connecting the dots is hardly a unique methodology; but when it is applied, it
is critical, first, that all the relevant dots be assembled; and, second, thateach be examined, in its own context, for its own significance, before apossible pattern is essayed. Plainly, a self-serving selection of events and aself-serving interpretation of each of those selected, may produce an accountapproximating verisimilitude, but it will not reflect what actually happened.
Accordingly, the Tribunal will consider the various ‘dots’ which Methanex has
adduced – one-by-one and then together with certain key events (essentially
additional, noteworthy dots) which Methanex does not adduce – in order toreach a conclusion about the factual assertions which Methanex has made.
(125)
Several initiatives were developed by academia, governmental bodies and even nongovernmental organizations to establish non-exhaustive lists containing the mostcommonly used red flags. (126) One of these initiatives is the ‘Toolkit for Arbitrators’
drafted by the Basel Institute on Governance. (127) This red flag list is inspired to acertain extent by arbitral cases dealing with claims of corruption and money laundering.
It is primarily concerned with situations involving the hiring of intermediaries or
consultants to conduct and facilitate business in a foreign country. More specifically,
arbitral tribunals are encouraged to exert further scrutiny into potential corrupt
practices if one or more of the following red flags emerge in the course of proceedings:

P 545(i) the intermediary does not have its seat/is not located in the country whereits/ his/ her services are performed; (ii) the commission paid to theintermediary is not in proportion to the work done and/or the expenses
claimed by the intermediary are not related to any actual expenses incurred;(ii) there is no tangible work product by the intermediary and theintermediary is unable to produce documentation for the services performed
and the services are not specified in any detail; (iii) the qualifications of theintermediary to perform the work for which it/ he/ she is hired are doubtful;(iv) the extent of time of the agent’s intervention is very short; (v) theintermediary demands payment to offshore accounts and/or via third parties
or unusual payment arrangements that raise local law issues; (vi) percentagebased remuneration; (vii) inaccurate or incomplete financial statements; (viii)
the intermediary demands payment of a commission or a significant portion
before the contract is concluded; (ix) the intermediary has no transparent
structure, an unclear financial organisation and hardly any staff (if theintermediary is a company); (x) the intermediary gets involved shortly before
the successful conclusion of a contract and/ or after unsuccessful negotiations
by the company; (xi) the intermediary is not bound by a code of conduct; (xii)
refusal to provide specific documents such as bank records or payments to athird party; (xiii) the intermediary asserts that it/ he/ she alone can secure thecontract, knowing the right people; (xiv) the intermediary has personal10© 2022 Kluwer Law International, a Wolters Kluwer Company. All rights reserved.

connections to decision-makers of the foreign state; (xv) lack of usual
documentation proving a normal commercial relationship (e.g. technicalstudies and research, negotiations, drafts of contracts, letters and emails);(xvi) the choice of the intermediary cannot be explained; no indicators thatthe intermediary was bound to be as efficient as competitors, proving that the
choice was not business oriented; (xvii) the contract is poorly drafted, or lacks
specific indications.
The Toolkit also describes several other indicators of corruption which are not related tothe hiring and use of intermediaries. Those include ‘the prevalence of corruptive
behaviour in the country as revealed by certain international organisations or NGOs likeTransparency International’s Corruption Perceptions Index’. The parties may rely on
NGOs’ reports in order to demonstrate the widespread nature of corruption in the hoststate. It must be noted, however, that such reports must necessarily be accompanied bycogent evidence relating specifically to the allegations of corruption raised by either
party to the arbitration proceedings. Arbitral tribunals have consistently refused toentertain allegations of corruption that were supported by mere insinuations derivingfrom general information (such as NGOs’ reports) about the state of corruption in the hoststate. The existence of such red flags or indicators of corruption warrants a careful andthorough analysis of the evidence adduced by the parties, but the fact remains that these‘dots’ must provide specific evidence of the acts of corruption in the case underconsideration.
Another indicator of corruption may also arise from the conduct of criminal investigations‘prior to the arbitration proceedings, or in the meantime, by domestic authorities’. Most
commentators usually establish a distinction depending on whether criminal
investigations were initiated by domestic criminal authorities or not. On the one hand,
the initiation and carrying out of an official investigation into the alleged criminal
activities begs the question of the evidentiary weight to be attributed to the outcome ofsuch investigation. It is generally accepted that arbitral tribunals are not necessarily
P 546 bound by the decisions adopted by domestic criminal authorities. (128) As the tribunal
in Glencore v. Colombia pointed out, the findings reached in the context of a domestic
criminal investigation may not so readily apply in relation to arbitral proceedings
because those proceedings ‘operate in different legal spheres’ and are ‘subject todiverging standards of proof’. (129) The fact remains, however, that such decisions are
relevant to the tribunal’s assessment of evidence of corruption, especially considering
the fact that domestic authorities ‘have a much higher capacity of investigation’ incomparison with arbitral tribunals. (130) This means that the outcome of domestic
criminal proceedings must be duly considered in the context of arbitration proceedings.
It is important to stress that the relevant decision must nevertheless offer evidence
relating specifically to the claim raised in the arbitration. A case in point in that respect
is Tethyan Copper v. Pakistan. (131) In that case, the respondent state alleged that theconclusion of the joint venture agreement giving rise to the dispute was affected bycorruption. In support of that allegation, it pointed out that the agreement was
concluded within an expedited timeframe following the entry into office of a newchairman for their public co-contractor. The respondent found it rather surprising, inparticular, that the agreement was concluded in a very limited timeframe after the newchairman took office despite the fact that the negotiations had stalled prior to thatevent. It was further submitted that the chairman involved in that process had previously
been convicted of corrupt practices by a domestic court. The tribunal nevertheless ruledout the relevance of that judgment on the ground that it was unrelated to the claimants’
investment. (132) Ultimately, it therefore falls upon arbitrators to decide whether theoutcome of domestic proceedings offers relevant and specific evidence of the alleged
illegal activities. In that context, the arbitral tribunal should also be mindful todetermine whether the domestic criminal proceedings were conducted in compliancewith due process requirements. (133)On the other hand, the arbitral case law also reveals that the absence of criminal
investigation may affect the outcome of a claim of corruption. The arbitral award handed
down in Sanum Investments v. Laos provides a perfect illustration of the implications
resulting from the lack of criminal investigation in relation to claims of corruption. The
tribunal considered that the host state’s failure to bring any prosecution or evenP 547 investigation against any of the individuals allegedly involved in corrupt practices was‘relevant to the credibility of the government’s allegations’. (134) The tribunal stressed, inparticular, that ‘the government’s failure to track down bribe-takers or to provide aconvincing explanation of its efforts (even if on occasion unsuccessful) to do so, weighsagainst the government’s case’. (135) In the light of the government’s failure to investigate
these issues, the respondent’s allegations were deemed as proven on the basis of thestandard of ‘balance of probabilities’, but were not established in accordance with thehigher standard of ‘clear and convincing evidence’. Several other arbitral tribunals havealso relied on the host state authorities’ failure to prosecute or investigate the alleged
criminal activities to dismiss such allegations. (136)
The absence of criminal investigation or prosecution may equally be taken into accountby national courts when they are called upon to ascertain whether an award iscompatible with international public policy. (137) That approach is hardly surprising11© 2022 Kluwer Law International, a Wolters Kluwer Company. All rights reserved.

considering the fact that governmental authorities are ‘best placed to investigate andcollect proof of corruption’. (138) The inaction of national authorities may therefore havesignificant implications in relation to the outcome of an allegation of corruption insofar
as it may deprive the tribunal of relevant evidence pertaining to the alleged criminal
activities. In Getma International v. Guinea, for instance, the tribunal observed that thebribed officials were not prosecuted or sanctioned for their alleged involvement in thecorruption scheme uncovered by the host state. It also added that they were still holding
positions within the state administration. The tribunal subsequently inferred from thoseelements that the state did not attach sufficient importance to the alleged corrupt
practices and, perhaps more importantly, that its inaction deprived that state from thepossibility to demonstrate corruption in accordance with the requisite standard of ‘clear
and convincing evidence’. (139) At the same time, however, it has been observed thatmost tribunals do not take the host state’s prosecution – or lack thereof – into accountP 548 when they are called upon to decide on allegations of corruption. (140) For that reason, it
is often suggested that the host state authorities’ failure to investigate the alleged
criminal activities does not as such constitute a ground for barring the underlying claimof corruption brought forward in arbitration proceedings. (141)

5 CONCLUDING REMARKSOver the past few years, a great deal has been written about the manner in which
allegations of corruption are – or perhaps ought to be – treated by the international
arbitration community at large. While there appears to be growing acceptance that theprohibition of corruption has ascended to the level of transnational public policy,
arbitrators and parties alike continue to grapple with considerable hurdles in the fightagainst corruption. Perhaps the most complex issue encountered by the arbitralcommunity relates to the evidence of corrupt activities. There is no denying that
allegations of corruption are generally difficult to demonstrate with absolute certainty.
That difficulty is further compounded in relation to international arbitration proceedings
because arbitrators enjoy rather limited investigative powers in comparison withdomestic courts and tribunals.
Against that background, this article has sought to offer a timely analysis of the arbitraljurisprudence relating to the rules and principles governing the evidence of corruption in
investment arbitration. The present analysis, conducted on the basis of forty awards
dealing with corruption in investment arbitration, indicates that in most instances itmatters relatively little which standard of proof applies in relation to allegations ofcorruption. What matters most, at the end of the day, is the tribunal’s approach to theassessment of evidence. It should come as no surprise, then, that in recent years arbitral
tribunals seem to have relied on their discretion in evidentiary matters to accept more
flexible sources of evidence. In the same vein, this article indicates that arbitral
tribunals are increasingly willing to address suspicions of corruption of their own motion
and, perhaps more importantly, make use of their fact-finding prerogatives in a more
P 548 systematic manner to alleviate the difficulty of demonstrating corruption.

References
*)
**)
1)
2)

3)
4)
5)

Professor at the Universities of Liège and Brussels, Member of the Brussels Bar.
Email: caprasse@caprasse-arbitration.com.
Research Assistant at the University of Liège. Email: mtecqmenne@uliege.be.
Aloysius P. Llamzon, Corruption in International Investment Arbitration 7–8 (Oxford
University Press 2014).
Bernardo M. Cremades & David J. A. Cairns, Trans-national Public Policy inInternational Arbitral Decision-Making: The Cases of Bribery, Money Laundering and
Fraud, in Arbitration – Money Laundering, Corruption and Fraud 67 (K. Karsten & A.
Berkeley eds., International Chamber of Commerce 2003); Christian Albanesi &Emmanuel Jolivet, Dealing With Corruption in Arbitration: A Review of ICC Experience,in ICC Special Supplement 2013: Tackling Corruption in Arbitration 28 (2013).
See also amongst others the Inter-American Convention Against Corruption and theConvention on the Fight Against Corruption involving Officials of the European
Communities or Officials of Member States of the European Union.
Inan Uluc, Corruption in International Arbitration, DPhil thesis, viii (Pennsylvania
State University 2016).
Kenneth D. Beale & Paolo Esposito, Emergent International Attitudes Towards Bribery,
Corruption and Money Laundering, 75 Arb. 360, 368 (2009).

12© 2022 Kluwer Law International, a Wolters Kluwer Company. All rights reserved.

6)

7)

8)

9)
10)

11)
12)

13)

14)
15)
16)

On the distinction between corruption as a bar to jurisdiction or admissibility, seee.g., Cameron A. Miles, Corruption, Jurisdiction and Admissibility in International
Investment Claims, 3 J. Int’l Disp. Settlement 329 (2012); Aloysius Llamzon & Anthony
C. Sinclair, Investor Wrongdoing in Investment Arbitration: Standards Governing Issuesof Corruption, Fraud, Misrepresentation and Other Investor Misconduct, in Legitimacy:
Myths, Realities, Challenges 500–503 (A. van den Berg ed., Kluwer Law International
2015). See also Lybia v. Nurool Insaat Ve Ticaret Anonim Sirketi, CA Paris, 28 Sep. 2021,
Rev. Arb. 1154 (2021), and note by Grégoire Bertrou, Hugues Piguet & Dmitry
Bayandin.
See e.g., Joachim Drude, Fiat Iustitia, ne pereat mundus: A Novel Approach to
Corruption and Investment Arbitration, 35 J. Int’l Arb. 665, 695 et seq. (2018); Caline
Mouawad & Jessica Beess und Chrostin, The Illegality Objection in Investor-State
Arbitration, 37 Arb. Int’l 57 (2021); Hiroyuki Tezuka, Corruption Issues in the
Jurisdictional Phase of Investment Arbitrations: An Arbitrator’s Checklist, in Addressing
Issues of Corruption in Commercial and Investment Arbitration 62–64 (D. Baizeau & R.
Kreindler eds, Kluwer Law International 2015); Stephan W. Schill, Illegal Investments
in Investment Treaty Arbitration, 11 L. & Prac. Int’l Cts. & Tribunals 281 (2012); Patrick
Dumberry, State of Confusion: The Doctrine of ‘Clean Hands’ in Investment Arbitration
After the Yukos Award, 17 J. World Inv. & Trade 229 (2016); Llamzon & Sinclair, supra n.
6, at 507–508; Andrea J. Menaker, The Determinative Impact of Fraud and Corruption
on Investment Arbitrations, 25 ICSID Rev. 67, 69–70 (2010); Aloysius Llamzon, On
Corruption’s Peremptory Treatment in International Arbitration, in Addressing Issues ofCorruption in Commercial and Investment Arbitration 39 (D. Baizeau & R. Kreindler
eds, Kluwer Law International 2015). See also Aloysius Llamzon, Yukos Universal
Limited (Isle of Man) v. The Russian Federation – The State of the ‘Unclean Hands’
Doctrine in International Investment Law: Yukos as both Omega and Alpha, 30 ICSID
Rev. 315 (2015); Yas Banifatemi, The Impact of Corruption on ‘Gateway Issues’ of
Arbitrability, Jurisdiction, Admissibility and Procedural Issues, in Addressing Issues ofCorruption in Commercial and Investment Arbitration 24–25 (D. Baizeau & R. Kreindler
eds, Kluwer Law International 2015); Jason W. Yackee, Investment Treaties andInvestor Corruption: An Emerging Defense for Host States?, 53 Va. J. Int’l L. 723, 738–739(2012).
Edoardo Marcenaro, Arbitrators’ Investigative and Reporting Rights and Duties on
Corruption, in Addressing Issues of Corruption in Commercial and Investment
Arbitration 141 (D. Baizeau & R. Kreindler eds, Kluwer Law International 2015).
Emmanuel Gaillard, The Emergence of Transnational Responses to Corruption inInternational Arbitration, 35 Arb. Int’l 1, 3 (2019).
Florian Haugeneder & Christoph Liebscher, Investment Arbitration – Corruption and
Investment Arbitration in Austrian Arbitration Yearbook 2009 543 (C. Klausegger et al.
eds, Stämpfli & Manz 2009); Matthias Scherer, Circumstantial Evidence in Corruption
Cases Before International Arbitral Tribunals, 5 Int’l ALR 29 (2002); Nassib G. Ziadé,
Addressing Allegations and Findings of Corruption: The Arbitrators’ Investigative andReporting Rights and Duties, in Addressing Issues of Corruption in Commercial andInvestment Arbitration 114 (D. Baizeau & R. Kreindler eds, Kluwer Law International
2015); Jean-Yves Garaud, L’Office de l’Arbitre en Arbitrage Commercial: Caractérisation
de l’Illicéité et Mise en Oeuvre des Sanctions, Rev. Arb. 173, 181 (2019).
Sophie Lemaire, La Preuve de la Corruption, Rev. Arb. 185, 189 (2020); Ziadé, supra n.
10.
This situation may occur in circumstances where the tribunal found that there wasno longer any dispute following the conclusion of a settlement between the parties(Azpetrol International Holdings BV, Azpetrol Group BV & Azpetrol Oil Services Group
BV v. Republic of Azerbaijan, ICSID Case No. ARB/06/15, Award (8 Sep. 2009)) or
because the claim was decided on another unrelated basis (Empresas Luchetti, SA &Luchetti Peru, SA v. Republic of Peru, ICSID Case No. ARB/03/4, Award (7 Feb. 2005)).
See also Cambodia Power Co. v. Kingdom of Cambodia, Electricité du Cambodge, ICSID
Case No. ARB/09/18, Decision on Jurisdiction (22 Mar. 2011); Pawlowski, AG & Projekt
Sever SRO v. Czech Republic, ICSID Case No. ARB/17/11, Award (1 Nov. 2021).
See e.g., Siemens AG v. Argentine Republic, ICSID Case No. ARB/02/8, Annulment andRevision Proceedings; Inceysa Vallisoletana SL v. Republic of El Salvador, ICSID Case
No. ARB/03/26, Award (2 Aug. 2006); F-W Oil Interests Inc. v. Republic of Trinidad andTobago, ICSID Case No. ARB/01/14, Award (3 Mar. 2006).
Sebastien Besson, Initiatives of Arbitrators: Where to Draw the Line Between Activism
and Passivity in Defining Issues in International Arbitration: Celebrating 100 Years of
the Chartered Institute of Arbitrators 223–229 ( J. C. Bétancourt ed., OUP 2016).
Convention on the Recognition and Enforcement of Foreign Arbitral Awards (NewYork Convention), Art. V(2)(b).
Similar arguments were also raised before the ICSID Annulment Committee in
Siemens v. Argentina, but these proceedings were dismissed following a settlement
between the parties. See Siemens AG v. Argentine Republic, supra n. 13.

13© 2022 Kluwer Law International, a Wolters Kluwer Company. All rights reserved.

17)

18)

19)

20)
21)
22)
23)
24)
25)
26)
27)
28)
29)

MK Group v. SARL Onix, CA Paris, 16 Jan. 2018, Rev. Arb. 401 (2018), and note by S.
Lemaire; Valeri Belokon v. Kyrgyz Republic, CA Paris, 21 Feb. 2017, Rev. Arb. 915 (2017),
and note by M. Audit; Alstom Transports, CA Paris, 28 May 2019, Rev. Arb. 850 (2019),
and note by Emmanuel Gaillard. On Alstom, see also the decision of the Cour deCassation quashing the Court of Appeal’s decision, but on an issue that is not
relevant for our discussion (Alstom Transports, Cass. Fr. (1 Ch. civ.), 29 Sep. 2021,
19.19.769).
Asaf Niemoj, The Limitations on Article 43 ICSID Convention: An (Un)limited Instrumentof the Tribunal?, 34 ICSID Rev. 697, 717 (2019); Pierre Mayer, L’Arbitre et l’Ordre Public,in Droit sans Frontières. Mélanges en l’Honneur du Professeur Éric Loquin 235(LexisNexis 2018).
Stephan W. Schill, Crafting the International Economic Order: The Public Function of
Investment Treaty Arbitration and Its Significance for the Role of the Arbitrator, 23
Leiden J. Int’l L. 401, 423 (2010); Besson, supra n. 14, at 235; Kathrin Betz, Economic
Crime in International Arbitration, 35 ASA Bull. 281, 287 (2017).
Schill, supra n. 19, at 423. See also Bernardo Cremades, Corruption and Investment
Arbitration, in Liber Amicorum in Honour of Robert Briner 203 (G. Aksen et al. eds, ICC
2005).
Ziadé, supra n. 10, at 114.
Llamzon, supra n. 1, at 228.
Emmanuel Gaillard, La Corruption Saisie par les Arbitres du Commerce International,
Rev. Arb. 805, 836–837 (2017).
Metal-Tech Ltd v. Republic of Uzbekistan, ICSID Case No ARB/10/3, Award (4 Oct.
2013), para. 200.
Ibid., para. 256.
Ibid., para. 265.
Joe Tirado, Matthew Page & Daniel Meagher, Corruption Investigation by
Governmental Authorities and Investment Arbitration: An Uneasy Relationship, 29
ICSID Rev. 493, 498 (2019).
Lemaire, supra n. 11, at 193.
Lao Holdings NV & Sanum Investments Ltd v. Government of the Lao People’s
Democratic Republic [2021] SGHC (I) 10.

30) Ibid., para. 153.
31) Gaillard, supra n. 23, at 836–837; Mayer, supra n. 18, at 241 et seq.; Domitille Baizeau

32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
42)
43)
44)
45)

46)

47)

& Tessa Hayes, The Arbitral Tribunal’s Duty and Power to Address Corruption Sua
Sponte, in International Arbitration and the Rule of Law: Contribution and Conformity
248–253 (A. Menaker ed., Kluwer Law International 2017). See also e.g., Metal-Tech Ltd
v. Republic of Uzbekistan, supra n. 24, paras 244 et seq.
See in that respect Baizeau & Hayes, supra n. 31, at 243–244; Niemoj, supra n. 18, at
717–718; Tezuka, supra n. 7, at 55.
Infinito Gold Ltd v. Republic of Costa Rica, ICSID Case No. ARB/14/5, Award (3 Jun.
2021).
Ibid., para. 178.
Ibid., para. 181.
Ibid.
Tezuka, supra n. 7, at 55–56.
Cremades & Cairns, supra n. 2, at 82.
Augustin Aynes, La Charge de la Preuve, Rev. Arb. 3, 6 (2020).
Simon Greenberg, Le Standard de la Preuve en Arbitrage International, Rev. Arb. 113,
114 (2020).
Kevin M. Clermont & Emily Sherwin, A Comparative View of Standards of Proof, 50 Am.
J. Comp. L. 243, 253–255 (2002).
Olivier Caprasse & Maxime Tecqmenne, La Preuve du Dommage en Arbitrage, Rev.
Arb. 156–157 (2020).
Patrick Kinsch, Entre Certitude et Vraisemblance, le Critère de la Preuve en Matière
Civile, in Mélanges en l’Honneur du Doyen Georges Wiederkehr – De Code en Code 455–
457 (Dalloz 2009).
See e.g., Andrea J. Menaker, Proving Corruption in International Arbitration, in
Addressing Issues of Corruption in Commercial and Investment Arbitration 78–79 (D.
Baizeau & R. Kreindler eds, Kluwer Law International 2015).
See e.g., ICC Arbitration Rules, Art. 19: ‘The proceedings before the arbitral tribunal
shall be governed by the Rules and, where the Rules are silent, by any rules which
the parties or, failing them, the arbitral tribunal may settle on, whether or notreference is thereby made to the rules of procedure of a national law to be applied
to the arbitration’.
Klaus Peter Berger, International Economic Arbitration 444 et seq. (Kluwer Law and
Taxation Publishers 1993); Jean-François Poudret & Sébastien Besson, Comparative
Law of International Arbitration 551 (Sweet and Maxwell 2007); Aynes, supra n. 39, at 7;
Greenberg, supra n. 40, at 127; Andreas Reiner, Burden and General Standards of
Proof, 10 Arb. Int’l 328, 331–332 (1994); Christophe Seraglini, Les Conflits de Loi en
Matière de Preuve dans l’Arbitrage International, Rev. Arb. 133, 145 (2020).
Jan Oostergetel & Theodora Laurentius v. Slovak Republic, UNCITRAL Award (23 Apr.
2012), para. 147. See also Metal-Tech Ltd v. Republic of Uzbekistan, supra n. 24, para.
238.

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48) See e.g., Lao Holdings NV v. Lao People’s Democratic Republic, ICSID Case No.

49)
50)
51)
52)
53)

54)
55)
56)

57)
58)
59)
60)

61)
62)
63)

64)

65)
66)

67)
68)
69)
70)

ARB(AF)/12/6, Award (6 Aug. 2019); Sanum Investments Ltd v. Government of the Lao
People’s Democratic Republic, PCA Case No. 2013-13, Award (6 Aug. 2019); Niko
Resources (Bangladesh) Ltd v. Bangladesh Petroleum Exploration & Production
Company Ltd (‘Bapex’), Bangladesh Oil Gas & Mineral Corp. (‘Petrobangla’), ICSID Case
No. ARB/10/11 and ICSID Case No. ARB/10/18, Decision on the Corruption Claim (25Feb. 2019); Getma International, NCT Necotrans, Getma International Investissements,
NCT Infrastructure & Logistique v. Republic of Guinea, ICSID Case No. ARB/11/29,
Award (16 Aug. 2016).
Seraglini, supra n. 46, at 142.
Ibid., at 139–141; Yu Hong-Lin, Adopting a ‘Range of Factors’ and ‘Division of Systems’
Approach: Establishing Principles for a Consistent Standard of Proof to Assess Illegality
in Foreign Investment Disputes, J. Bus. L. 75, 85–86 (2021).
Cremades, supra n. 20, at 210.
Kabir A. N. Duggal, Principles of Evidence in Investor-State Arbitration 222–223 (DPhil
thesis, Universiteit Leiden 2019).
See e.g., ICSID Convention Arbitration Rules, rule 34(1) (‘The arbitral tribunal shall be
the judge of the admissibility of any evidence adduced and of its probative value’);
UNCITRAL Arbitration Rules, Art. 27(4) (‘The arbitral tribunal shall determine theadmissibility, relevance, materiality and relevance of the evidence offered’).
Mateus Aimoré Carreteiro, Standard of Proof in International Arbitration: Proposed
Guidelines for Promoting Predictability, 49 Revista Brasileira Arbitragem 82, 94 (2016).
Georg Gavrilovic & Gavrilovic DOO v. Republic of Croatia, ICSID Case No. ARB/12/39,
Award (26 Jul. 2018), para. 229.
Duggal, supra n. 52, at 40; Jérôme Ortscheidt, La Réparation du Dommage dansl’Arbitrage Commercial International 38 (Dalloz 2001). See e.g., ICC Case No. 6497, ICC
8891, ICC 12990 No. 251; The Rompetrol Group NV v. Romania, ICSID Case No
ARB/06/03, Award (29 Apr. 2013), para. 178; Dadras International & Per-Am
Construction Corp. v. Islamic Republic of Iran & Tehran Redevelopment Company,
IUSCT Case No. 567-213/215-3 (7 Nov. 1995), para. 120.
UNCITRAL Arbitral Rules, Art. 27: ‘1. Each party has the burden of proving the facts
relied on to support its claim or defence’.
Ibid., Art. 24: ‘1. Each party shall have the burden of proving the facts relied on to
support his claim or defence’.
Aynes, supra n. 39, at 6.
Frédéric G. Sourgens, Kabir Duggal & Ian A. Laird, Evidence in International
Investment Arbitration 24 (OUP 2018); Mojtaba Kazazi, Burden of Proof and Related
Issues – A Study on Evidence Before International Tribunals 221 et seq. (Kluwer Law
international 1996). See also Metal-Tech Ltd v. Republic of Uzbekistan, supra n. 24,
para. 237.
Aynes, supra n. 39, at 5.
Mathilde Frappier, Actualités de la Condition de Conformité de l’Investissement
Étranger au Droit Interne de l’État Hôte, Paris J. Int’l Arb. 741, 749 (2019).
Uluc, supra n. 4, at 156. See e.g., Waguih Elie George Siag & Clorinda Vecchi v. Arab
Republic of Egypt, ICSID Case No ARB/05/15, Award (1 Jun. 2009), para. 317; Jan
Oostergetel & Theodora Laurentius v. Slovak Republic, supra n. 47, para. 148; The
Rompetrol Group NV v. Romania, supra n. 56, para. 178; Apotex Holdings Inc. & Apotex
Inc. v. United States of America, NAFTA/ICSID Case No ARB(AF)/12/1, Award (25 Aug.
2014) Part VIII, para. 8.8; Metal-Tech Ltd v. Republic of Uzbekistan, supra n. 24, para.
238; Fraport AG Frankfurt Airport Services Worldwide v. Republic of the Philippines,
ICSID Case No ARB/11/12, Award (10 Dec. 2014), para. 299; Karkey Karadeniz Elektrik
Uretim AS v. Islamic Republic of Pakistan, ICSID Case No ARB 13/1, Award (22 Aug.
2017), para. 497.
Menaker, supra n. 44, at 80–81; Duggal, supra n. 52, at 142; Anna Magdalena
Kubalczyk, Evidentiary Rules in International Arbitration – A Comparative Analysis ofApproaches and the Need for Regulation, 3 Groningen J. Int’l L. 85, 105 (2015). See e.g.,
Ioannis Kardassopoulos & Ron Fuchs v. Republic of Georgia, ICSID Case Nos
ARB/05/18 and ARB/07/15, Award (3 Mar. 2010), para. 229; Bern von Pezold and others
v. Republic of Zimbabwe, ICSID Case No ARB/10/15, Award (28 Jul. 2015), para. 177.
Hong-Lin, supra n. 50, at 80.
See e.g., Waguih Elie George Siag & Clorinda Vecchi v. Arab Republic of Egypt, supra n.
63, para. 326; EDF (Services) Ltd v. Romania, ICSID Case No Arb/05/13, Award (8 Oct.
2009), para. 64; Dadras International & Per-Am Construction Corp. v. Islamic Republicof Iran & Tehran Redevelopment Co., supra n. 56, paras 123–124.
See e.g., Tokios Tokelés v. Ukraine, ICSID Case No ARB/02/18, Award (27 Jul. 2007); The
Rompetrol Group NV v. Romania, supra n. 56, para. 181.
Cecily Rose, Questioning the Role of International Arbitration in the Fight Against
Corruption, 31 J. Int’l Arb. 183, 193 (2014).
Aikaterini Florou, Adverse Inferences and Penalty Default Rules in International
Investment Arbitration: A Policy Approach to the Production of Evidence, 10 J. Int’l
Disp. Settlement 423, 424 (2019); Scherer, supra n. 10, at 31.
Duggal, supra n. 52, at 131; Albanesi & Jolivet, supra n. 2, at 31; Uluc, supra n. 4, at 181;
Nathan D. O’Malley, Rules of Evidence in International Arbitration: An Annotated Guide
209–210 (Informa Law 2012).

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71)

72)
73)

74)
75)

See e.g., Karkey Karadeniz v. Pakistan, supra n. 63, paras 492–493; Waguih Elie George
Siag & Clorinda Vecchi v. Arab Republic of Egypt, supra n. 63, para. 326; Unión FenosaGas SA v. Arab Republic of Egypt, ICSID Case No. ARB/14/4, Award (31 Aug. 2018), para.
7.52.
Bayindir Insaat Turizm Ticaret Ve Sanayi AS v. Islamic Republic of Pakistan, ICSID Case
No. ARB/03/29, Award (27 Aug. 2009), paras 142–143.
See e.g., Dadras International & Per-Am Construction Corp. v. Islamic Republic of Iran
& Tehran Redevelopment Co., supra n. 56, paras 123–124; Waguih Elie George Siag &Clorinda Vecchi v. Arab Republic of Egypt, supra n. 63, para. 326; African Holding Co. of
America, Inc. & Société Africaine de Construction au Congo SARL v. Democratic
Republic of the Congo, ICSID Case No. ARB/05/21, Award on the Objections toJurisdiction and Admissibility (29 Jul. 2008), para. 52.
Greenberg, supra n. 40, at 116.
Vibe Ulfbeck & Marie-Louise Holle, Tort Law and Burden of Proof – Comparative
Aspects. A Special Case for Entreprise Liability?, in European Tort Law 2008 29 (H.
Koziol & B. C. Steininger eds, Springer 2009).

76) Aimoré Carreteiro, supra n. 54, at 87.
77) Ibid., at 87–88.
78) Ibid., at 88. See also Michele Taruffo, Rethinking the Standards of Proof, 51 Am. J.

Comp. L. 666 (2003).

79) Mark Schweizer, The Civil Standard of Proof – What Is It Actually?, 20 Int’l J. Evid. &

80)

81)
82)
83)

84)
85)
86)
87)

88)
89)
90)
91)
92)

93)

Proof 217, 220 et seq. (2016); Bernard Hanotiau, Satisfying the Burden of Proof: The
Viewpoint of a Civil Law Lawyer, 10 Arb. Int’l 341, 345–346 (1994); Kinsch, supra n. 43, at
458–463.
Sophie Cuykens, Damien Holzapfel & Laurent Kennes, La Preuve en Matière Pénale 25(Larcier 2015). See also Swiss Criminal Procedure Code, Art. 10: ‘Where there isunsurmountable doubt as to whether the factual requirements of alleged offence
have been fulfilled, the court shall proceed on the assumption that thecircumstances more favourable to the accused occurred’.
Caprasse & Tecqmenne, supra n. 42, at 156–157.
Greenberg, supra n. 40, at 120.
See amongst others Haugeneder & Liebscher, supra n. 10, at 546; O’Malley, supra n.
70, at 208; Vera Han Houtte, Adverse Inferences in International Arbitration, in Written
Evidence and Discovery in International Arbitration: New Issues and Tendencies 198 (T.
Giovannini & A. Mourre eds, Dossiers ICC Institute of World Business Law 2009);
Reiner, supra n. 46, at 335.
Hong-Lin, supra n. 50, at 80. In a similar vein, see also Duggal, supra n. 52, at 146;
Caprasse & Tecqmenne, supra n. 42, at 156–157.
Niko Resources (Bangladesh) Ltd v. Bangladesh Petroleum Exploration & Production
Co. Ltd (‘Bapex’), Bangladesh Oil Gas & Mineral Corp. (‘Petrobangla’), supra n. 48,
para. 805.
Gaillard, supra n. 9, at 4. See also Gaillard, supra n. 23, at 834–835.
See e.g., Cortec Mining Kenya Ltd, Cortec (Pty) Ltd & Stirling Capital Ltd v. Republic of
Kenya, ICSID Case No. ARB/15/29, Award (22 Oct. 2018); Quiborax SA & Non Metallics
Minerals SA v. Plurinational State of Bolivia, ICSID Case No. ARB/06/2, Award (16 Sep.
2015); Churchill Mining PLC & Planet Mining Pty Ltd v. Republic of Indonesia, ICSID
Case Nos ARB/12/14 and 12/40, Award (6 Dec. 2016); Methanex Corp. v. United Statesof America, UNCITRAL/Nafta Award (3 Aug. 2005); Jan Oostergetel & Theodora
Laurentius v. Slovak Republic, UNCITRAL Ad hoc Award (13 Apr. 2012); Azurix Corp. v.
Argentine Republic, ICSID Case No. ARB/01/12, Award (14 Jul. 2006); Sistem
Mühendislik Insaat Sanayi AS v. Kyrgyz Republic, ICSID Case No. ARB(AF)/06/1, Award(9 Sep. 2009); Southern Pacific Properties (Middle East) Ltd v. Arab Republic of Egypt,
ICSID Case No. ARB/84/3, Award (20 May 1992); International Thunderbird Gaming
Corp. v. United Mexican States, UNCITRAL/NAFTA Award (26 Jan. 2006), para. 150.
Bridgestone Licensing Services, Inc. & Bridgestone Americas, Inc. v. Republic ofPanama, ICSID Case No. ARB/16/34, Award (14 Aug. 2020).
ECE Projektmanagement International GmbH v. Kommanditgesellschaft Panta
Achtundsechzigste Grundstücksgesellschaft mbH & Co. v. Czech Republic, PCA CaseNo. 2010-5, Award (19 Sep. 2013).
Ibid., para. 4.879.
See in contrast, Metal-Tech Ltd v. Republic of Uzbekistan, supra n. 24, paras 237–238.
See also Waguih Elie George Siag & Clorinda Vecchi v. Arab Republic of Egypt, supra n.
63, para. 326; Vladislav Kim, Pavel Borissov, Aibar Burkitbayev, Almas Chukin, Lyazzat
Daurenbekova, Adal Issabekov, Damir Karazzayev, Aidan Karibzhanov, Aigul
Nurmakhanova, Kairat Omarov, Nikolay Varenko & Gulzhamash Zaitbekova v.
Republic of Uzbekistan, ICSID Case No. ARB/13/6, Decision on Jurisdiction (8 Mar.
2017), para. 545.
Republic of Croatia v. Mol Hungarian Oil & Gas Plc, PCA Case No. 2014-15, Award (23Dec. 2016), paras 107–113.

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94) See e.g., Tethyan Copper Company Pty Ltd v. Islamic Republic of Pakistan, ICSID Case

No. ARB/12/1, Decision on Respondent’s Application to Dismiss the Claims (withreasons) (10 Nov. 2017), paras 283–306; EDF (Services) Ltd v. Romania, supra n. 66,
para. 221; Getma International, NCT Necotrans, Getma International Investissements,
NCT Infrastructure & Logistique v. Republic of Guinea, supra n. 48, paras 181–184;
Union Fenosa Gas SA v. Arab Republic of Egypt, ICSID Case No. ARB/14/4, Award (31Aug. 2018), para. 7.52; The Rompetrol Group NV v. Romania, supra n. 56, paras 181–183.
95) See e.g., Fraport AG Frankfurt Airport Services Worldwide v. Republic of the Philippines,
supra n. 63, para. 479; Georg Gavrilovic & Gavrilovic DOO v. Republic of Croatia, supran. 55, paras 233–398; Liman Caspian Oil BV & NCL Dutch Investment BV v. Kazakhstan,
ICSID Case No ARB/07/14, Award (22 Jun. 2010), para. 422.
96) Sourgens, Duggal & Laird, supra n. 60, at 85.
97) See e.g., Oil Fields of Texas, Inc. v. Government of the Islamic Republic of Iran &National Iranian Oil Co., IUSCT Case No. 43, Award (8 Oct. 1986), para. 25; Bayindir
Insaat Turizm Ticaret Ve Sanayi AS v. Islamic Republic of Pakistan, supra n. 72, paras
142–143.
98) African Holding Co. of America, Inc. & Société Africaine de Construction au Congo SARL
v. Democratic Republic of the Congo, supra n. 73, para. 52.
99) Westinghouse International Projects Company, Westinghouse Electric SA,
Westinghouse Electric Corp., & Burns & Roe Enterprises, Inc. v. National Power Corp.,
Republic of Philippines, ICC Case No. 6401, Preliminary Award (19 Dec. 1991), para. 104;
Westacre Investment Inc. v. Jugoimport-SDPR Holding Co. Ltd & ors, ICC Case No. 7047,
Award (28 Feb. 1994); Dadras International & Per-Am Construction Corp. v. Islamic
Republic of Iran & Tehran Redevelopment Co., supra n. 56, paras 123–124; Rumeli
Telekom AS & Telsim Mobil Telekomikasyon Hizmetleri AS v. Republic of Kazakhstan,
ICSID Case No. ARB/05/16, Award (29 Jul. 2008), para. 709; Waguih Elie George Siag &Clorinda Vecchi v. Arab Republic of Egypt, supra n. 63, para. 326; EDF (Services) Ltd v.
Romania, supra n. 66, para. 64; Liman Caspian Oil BV & NCL Dutch Investment BV v.
Kazakhstan, supra n. 95, paras 422–424; Karkey Karadeniz v. Pakistan, supra n. 63,
paras 492–493.
100) Sourgens, Duggal & Laird, supra n. 60, at 85.
101) Karkey Karadeniz v. Pakistan, supra n. 63, para. 492.
102) Lao Holdings NV v. Lao People’s Democratic Republic, supra n. 48, para. 110; Sanum
Investments Ltd v. Government of the Lao People’s Democratic Republic, supra n. 48,
para. 108; EDF (Services) Ltd v. Romania, supra n. 66, para. 221; Fraport AG Frankfurt
Airport Services Worldwide v. Republic of the Philippines, supra n. 63, para. 479; African
Holding Co. of America, Inc. & Société Africaine de Construction au Congo SARL v.
Democratic Republic of the Congo, supra n. 73, para. 52; Valeri Belokon v. Kyrgyz
Republic, UNCITRAL Award (24 Oct. 2014), para. 148; Liman Caspian Oil BV & NCL
Dutch Investment BV v. Kazakhstan, supra n. 95, paras 422–424; Rumeli Telekom AS &Telsim Mobil Telekomikasyon Hizmetleri AS v. Republic of Kazakhstan, supra n. 99,
para. 709; Karkey Karadeniz v. Pakistan, supra n. 63, para. 492; Waguih Elie George
Siag & Clorinda Vecchi v. Arab Republic of Egypt, supra n. 63, para. 326.
103) Union Fenosa Gas SA v. Arab Republic of Egypt, supra n. 94, para. 7.52; The Rompetrol
Group NV v. Romania, supra n. 56, paras 181–183; Georg Gavrilovic & Gavrilovic DOO v.
Republic of Croatia, supra n. 55, para. 398.
104) Glencore International AG & CI Prodeco SA v. Republic of Colombia, ICSID Case No.
ARB/16/6, Award (27 Aug. 2019), para. 669.
105) Republic of Croatia v. Mol Hungarian Oil & Gas Plc, supra n. 93, para. 113; Tethyan
Copper Co. Pty Ltd v. Islamic Republic of Pakistan, supra n. 94, para. 402; Getma
International, NCT Necotrans, Getma International Investissements, NCT Infrastructure& Logistique v. Republic of Guinea, supra n. 48, para. 184; Metal-Tech Ltd v. Republicof Uzbekistan, supra n. 24, para. 243.
106) Éric Teynier, L’Office de l’Arbitre d’Investissement: Le Cas Particulier del’Investissement Illicite, Rev. Arb. 117, 165 (2017).
107) Paul Stothard & Lolan Sagoe-Moses, Proving Corruption Allegations in International
Arbitration – A Return to the Balance of Probabilities Standard?, 15 Int’l Arb. Rep. 29,
30 (2020).
108) See e.g., Belgian Judiciary Code, Art. 1708.
109) Chevron Corp. & Texaco Petroleum Co. v. Republic of Ecuador, UNCITRAL Second
Partial Award on Track II (30 Aug. 2018), para. 4.24.
110) Constantine Partasides, Proving Corruption in International Arbitration: A Balanced
Standard for the Real World, 25 ICSID Rev. 47, 58 (2010).
111) Haugeneder & Liebscher, supra n. 10, at 556.
112) Lemaire, supra n. 11, at 191–192.
113) Llamzon, supra n. 1, at 201.
114) See also Waguih Elie George Siag & Clorinda Vecchi v. Arab Republic of Egypt, supra n.
66, Dissenting Opinion of Prof. Francisco Orrego Vicuña (of the Award) (11 May 2009).
115) Lao Holdings NV v. Lao People’s Democratic Republic, supra n. 48; Sanum Investments
Ltd v. Government of the Lao People’s Democratic Republic, supra n. 48.
116) Sanum Investments Ltd v. Government of the Lao People’s Democratic Republic, supra
n. 48, para. 158.
117) Ibid., para. 161.
118) Ibid., para. 177.

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119) Diana A. A. Reisman, Apportioning Fault for Performance Corruption in Investment

Arbitration, 37 Arb. Int’1 8 (2021).

120) Metal-Tech Ltd v. Republic of Uzbekistan, supra n. 24; World Duty Free Co. Ltd v.

Republic of Kenya, ICSID Case No. ARB/00/7, Award (4 Oct. 2006); Spentex
Netherlands BV v. Republic of Uzbekistan, ICSID Case No. ARB/13/26, Award (27 Dec.
2016); Chevron Corp. & Texaco Petroleum Co. v. Republic of Ecuador, supra n. 109.
121) Metal-Tech Ltd v. Republic of Uzbekistan, supra n. 24, paras 239–243. See also World
Duty Free Co. Ltd v. Republic of Kenya, supra n. 120.
122) In investment arbitration, see e.g., Metal-Tech Ltd v. Republic of Uzbekistan, supra n.
24, para. 243; Spentex Netherlands BV v. Republic of Uzbekistan, supra n. 120; Fraport
AG Frankfurt Airport Services Worldwide v. Republic of the Philippines, supra n. 63,
para. 497. In commercial arbitration, see e.g., ICC Case Nos 3916, 6497, 8891, 12990,
15908. In national jurisprudence, see e.g., Customs and Tax Consultancy LLC v.
République Démocratique du Congo, CA Paris, 16 May 2017, Rev. Arb. 248 (2018), andnote by Jean-Baptiste Racine; Valeri Belokon v. Kyrgyz Republic, supra n. 17, and noteby M. Audit; Alstom Transports, supra n. 17, and note by Emmanuel Gaillard; Airbus
Helicopters SAS, CA Paris, 15 Sep. 2020, Rev. Arb. 1084 (2020), and note by Andrea
Pinna. See also Gaillard, supra n. 23, at 877–883.
123) Gaillard, supra n. 9, at 4.
124) Garaud, supra n. 10, at 185; Scherer, supra n. 10, at 31.
125) Methanex Corp. v. United States of America, supra n. 87, Part III, Ch. B, para. 3.
126) See e.g., United States Foreign Corrupt Practices Act (1977) as well as the Woolf
Committee report entitled ‘Business Ethics, Global Companies and the Defence
Industry’.
127) Basel Institute on Governance, Corruption and Money Laundering in International
Arbitration – A Toolkit for Arbitrators (Basel 2019).
128) Teynier, supra n. 106, at 160.
129) Glencore International AG & CI Prodeco SA v. Republic of Colombia, supra n. 104, para.
673.
130) Ibid., para. 674.
131) See also Methanex Corp. v. United States of America, supra n. 87; ECE
Projektmanagement v. Czech Republic, supra n. 89, para. 4.885.
132) Tethyan Copper Co. Pty Ltd v. Islamic Republic of Pakistan, supra n. 94, para. 394.
133) Teynier, supra n. 106, at 160–161; Frappier, supra n. 62, at 750. See e.g., Karkey
Karadeniz v. Pakistan, supra n. 63, paras 550–551; Republic of Croatia v. Mol Hungarian
Oil & Gas Plc, supra n. 93, para. 138.
134) Sanum Investments Ltd v. Government of the Lao People’s Democratic Republic, supra
n. 48, para. 111.
135) Ibid., para. 158.
136) See in particular, Vladislav Kim & ors v. Republic of Uzbekistan, supra n. 92, para. 575;
Wena Hotels Ltd v. Arab Republic of Egypt, ICSID Case No. ARB/98/4, Award (8 Dec.
2000), paras 111–116; Glencore International AG & CI Prodeco SA v. Republic ofColombia, supra n. 104, para. 738.
137) Republic of Congo v. Commisimpex, CA Paris, 14 Oct. 2014, 13/03410.
138) Niko Resources v. Bangladesh, supra n. 48, Decision on Jurisdiction (19 Aug. 2013),
para. 425.
139) Getma International, NCT Necotrans, Getma International Investissements, NCT
Infrastructure & Logistique v. Republic of Guinea, supra n. 48, paras 224–225.
140) Marie Stoyanov, Werner Eyskens, Valentin Bourgeois & Michaël Fernandez-Bertier,
Procedural Interplay Between Investment Arbitration and Criminal Proceedings in theContext of Corruption Allegations, b-Arbitra 7, 16–17 (2018).
141) Teynier, supra n. 106, at 149–150; Brody Greenwald, The Viability of Corruption
Defenses in Investment Arbitration When the State Does not Prosecute, EJILTalk (15Apr. 2015), www.ejiltalk.org/the-viability-of-corruption-defenses-in-investmentarbitration-when-the-state-does-....

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