SECOND SECTION
 
 
 
 
 
 
CASE OF VAN WESENBEECK v. BELGIUM
 
(Applications nos. 67496/10 and 52936/12)
 
 
 
 
 
JUDGMENT
(extracts)
 
 
STRASBOURG
 
23 May 2017
 
FINAL
 
18/09/2017
 
 
This judgment is final in the circumstances set out in Article 44 § 2 of the Convention. It may be subject to editorial revision. In the case of van Wesenbeeck v. Belgium,
The European Court of Human Rights (Second Section), sitting as a Chamber composed of:
 Işıl Karakaş, President,
 Julia Laffranque,
 Paul Lemmens,
 Valeriu Griţco,
 Ksenija Turković,
 Stéphanie Mourou-Vikström,
 Georges Ravarani, judges,
and Hasan Bakırcı, Deputy Section Registrar,
Having deliberated in private on 4 April 2017,
Delivers the following judgment, which was adopted on that date:
PROCEDURE
1. The case originated in two applications (nos. 67496/10 and 52936/12) against the Kingdom of Belgium lodged with the Court under Article 34 of the Convention for the Protection of Human Rights and Fundamental Freedoms (“the Convention”) by a Dutch national, Mr Adrianus van Wesenbeeck (“the applicant”), on 19 November 2010. 2. The applicant was represented by Mr G.G.J. Knoops and Mr L Delbrouck, lawyers practising in Amsterdam. The Belgian Government (“the Government”) were represented by their Agent, Mr M. Tysebaert, General Adviser, Federal Department of Justice. 3. The applicant complained that he had not benefited from a fair trial within the meaning of Article 6 § 1 of the Convention on the grounds that his defence rights had not been respected and that he had not been allowed to question the undercover agents involved pursuant to Article 6 § 3 (d). 4. On 18 March 2015 those complaints were communicated to the Government and the remainder of the applications was declared inadmissible pursuant to Rule 54 § 3 of the Rules of Court. 5. By letter of 23 March 2015 the Dutch Government were informed of the possibility of submitting written observations under Article 36 § 1 of the Convention and Rule 44 if they so wished. The Dutch Government did not avail themselves of their right to intervene. THE FACTS
I. THE CIRCUMSTANCES OF THE CASE
6. The applicant was born in 1961 and lives in Beveren. A. Inquiry and judicial investigation phases
7. On 10 May 2006 the Hasselt public prosecutor, pursuant to Article 28bis § 2 of the Code of Criminal Procedure (“CIC”), gave prior written agreement for the instigation of a proactive investigation against the applicant and several other suspects, on suspicion of drug trafficking, involvement in an international criminal organisation and money laundering. The proactive investigation included using the special investigative method of infiltration. On 1 August 2006 the public prosecutor also authorised the use of the special investigative method of observation. 8. Pursuant to Articles 47septies § 1 and 47nonies § 1 CIC, a separate confidential case file was established (see paragraphs 47-49 below). 9. The proactive investigation continued until 17 September 2008. On that date a report was drawn up by the police officer in charge summarising all the evidence gathered, summarising all the evidence gather in the framework of the proactive investigation. That report was followed by two more reports on 18 September 2008, one on the infiltration and the other on the observation operation, describing the evidence specifically gathered by means of those two special investigative measures. The three reports were added to the criminal file, which was subsequently to be made accessible to the defendants. 10. By two decisions issued on 18 September 2008 the public prosecutor confirmed that authorisations had been given for both the observation and the infiltration operations. 11. On 18 September 2008 the public prosecutor requested the investigating judge of the Hasselt Court of First Instance to instigate a judicial investigation. A “traditional” reactive investigation ensued, conducted by the investigating judge. In addition to the observation and infiltration operations, recourse was had to phone-tapping and international mutual legal assistance. 12. A report drawn up on 25 September 2008 by the police officer in charge mentioned information on the existence of a criminal organisation which had served as the grounds for using observation and infiltration at the proactive search stage, as well as the confirmations obtained in the framework of the said special investigative measures. 13. On 20 October 2008 the Federal Prosecutor’s Office took over the case from the Hasselt public prosecutor. The investigation remained under the oversight and authority of the Hasselt investigating judge. 14. The observation and infiltration operations ended on 14 June 2009. On that date several suspects, including the applicant, were arrested and placed in pre-trial detention. 15. By written submissions of the Federal Prosecutor of 29 December 2009, the Indictments Division of the Antwerp Court of Appeal was instructed to verify, pursuant to Article 235ter CIC, the conformity of the confidential file with the evidence contained in the criminal case file and to ensure that there were no irregularities (see paragraphs 50-54 below). During the proceedings, the parties requested that the court also verify the lawfulness of the procedure followed under Article 235bis CIC (see paragraph 55 below). 16. At a hearing on 2 March 2010 the Indictments Division heard the Federal Prosecutor separately, in the absence of the parties. On that occasion, the confidential case file was made available to the Division. Subsequently, several defendants, including the applicant, were invited to present their case, assisted by their lawyers. 17. By interim judgment of 20 May 2010, the Indictments Division stated that, as regards the scrutiny of the special investigative measures, it had to verify the information in the confidential file concerning not only the reactive investigation but also the proactive one. It further held that some evidence concerning the special investigative measures had yet to be added to the criminal file. It ordered the reopening of proceedings so that the Federal Prosecutor’s Office could complete the files. 18. Following that judgment, the aforementioned decisions of 18 September 2008 and the report established on 25 September 2008 (see paragraphs 10 and 12 above) were added to the criminal file pursuant to Articles 47septies and 47novies CIC. 19. By judgment of 24 June 2010, the Indictments Division declared the criminal file complete, stating that no nullity, irregularity or violation of legal or Convention provisions had been found (see Article 235bis CIC), and that no irregularities had been committed in implementing the special investigative methods (see Article 235ter CIC). 20. As regards in particular the use of those methods during the proactive investigation, the division stated the following:
“The proactive investigation, including the special investigative methods of observation and infiltration, fulfilled the conditions of Articles 28bis, 47sexies and 47octies of the Code of Criminal Procedure. The strong prima facie evidence of the offences charged and the reasonable suspicion as defined in Article 28bis of the Code of Criminal Procedure were present, transpiring [from the reports of 25, 17 and 18 September 2008]. Those reports of 17 and 18 September 2008 also confirm that the ‘maximum’ limit of the proactive investigation was complied with. It was thus found, on the one hand, that the overview of the case had been sufficiently established, and on the other, that sufficiently serious indications had been obtained to instigate a reactive investigation. Those serious indications had been reflected in the summary written conclusions in response from the public prosecutor’s office. In that context, the discovery on 15 August 2008 of a debit indicator left by V.W. had been decisive. The reports in question demonstrate that the special investigative methods used during the proactive investigation met the conditions of proportionality and subsidiarity.”
... 22. The applicant lodged an appeal on points of law against the judgment of 24 June 2010. That appeal was dismissed by judgment of the Court of Cassation on 21 September 2010. Relying on Article 6 of the Convention, the applicant complained that the criminal file contained neither the report on the basis of which the public prosecutor had instigated a proactive investigation on 10 May 2006 nor the documents relating to that proactive investigation. Those pleas were dismissed on the grounds that they required a factual assessment which the Court of Cassation was unable to conduct. 23. By order of the Hasselt Court of First Instance sitting in private session on 29 September 2010, seventeen defendants, including the applicant, were committed to stand trial. B. Proceedings before the trial courts
24. On 16 March 2011 the applicant was sentenced to ten years’ imprisonment and fined 137,500 euros by the Hasselt Court of First Instance for drug trafficking, involvement in an international criminal organisation and money laundering. It transpires from the almost 160-page judgment that the establishment of the facts stemmed partly from evidence gather by means of the special investigative methods.
... 27. As regards the applicant’s request for a face-to-face meeting with the undercover agents, the court ruled as follows:
“Having regard to the procedure followed, to the proceedings relating to the special investigative methods implemented in the Indictments Division from the judicial investigation to the hearing stage, to the evidence before us, to the fact that two undercover agents drew up a report and that their results were compared, to the fact that the defendants were able to call witnesses and therefore, in particular at the request of the [applicant] and the second defendant, witnesses were heard in connection with the [applicant’s] statements on the undercover agents, and to the fact that the court and the defendants were able to compare the reports on the evidence gathered by the undercover agents with such objective facts as the items discovered during the searches (e.g. the card), the conversation between the undercover agent Billy and the [applicant], SMS messages (e.g. between the [applicant] and Billy) and telephone conversations (e.g. the conversation with the third defendant), the court considers it unnecessary for the establishment of the truth, the exercise of the rights of the defence and the safeguard on a fair trial for the undercover agents to be heard.
... Furthermore, regard must be had to the aspect of the undercover agents’ safety and security and the importance of anonymity, inter alia from the angle of their possible involvement in other cases. In the present case this aspect is especially important given that the infiltration continued over several years and that friendly links had grown up between the agents and several defendants and their partners. During the preliminary investigation photographs of the undercover agents were apparently published on the Internet to alert others to their undercover status. In view of the friendships formed and the content of certain telephone conversations (including those between the [applicant] and the third defendant) ... the risk of reprisals is very real.
... Lastly, it should be noted that it is unclear what specific questions they wish to put to the undercover agents. The [applicant] and the second defendant only wish to put questions to the undercover agent Billy concerning the recovery of the debit indicator allegedly thrown away by the [applicant]. However, since the undercover agent’s submission on this point is set out in the report included in the criminal file it is unnecessary to hear the undercover agent on this question. The Indictments Division, which is an independent tribunal, held that the reports corresponded to the confidential file. The defendants have an opportunity at the hearing to put forward their pleas concerning the recovery of the debit indicator and to contradict the undercover agent’s version.”
28. The court replied to the applicant’s plea that he had been unable to verify whether an undercover agent had been engaged in incitement to crime in the present case as follows:
“In the present case the undercover agent only acted in the framework of the offence mentioned in point C of the indictment. [That offence] covered the period from January to June 2009, whereas the judicial investigation had begun on 18 September 2008. On the basis, inter alia, of the regular reports on the undercover work which were submitted during the judicial investigation and the text messages and telephone calls tapped, the agreements and transactions relating to those facts, as well as the prior operations, [were] scrutinised. This information shows that there was no incitement to crime. That is, moreover, confirmed by the fact that other offences of possession, sale, import and export of drugs or psychotropic substances were established in which the undercover agents had played no part.”
29. On 23 June 2011 the Antwerp Court of Appeal upheld the first-instance judgment in absentia. 30. On appeal, and following adversarial proceedings, the same court delivered a judgment on 13 October 2011 confirming the first-instance judgment decision in the same terms as before. As he had done before the Court of First Instance, the applicant had requested that the Court of Appeal allow a face-to-face meeting with the undercover agents in order to assess the reliability of their statements. The Court of Appeal dismissed the request with reference to the reasoning of the impugned judgment. It added that it only ascribed relative evidentiary value to the statements of the undercover agents, and that the truth and proof of guilt had also been established on the basis of other evidence. Furthermore, since the applicant had refused to appear at first instance and on appeal, the request for a face-to-face meeting seemed rather academic. 31. Relying, inter alia, on Article 6 of the Convention the applicant lodged an appeal on points of law with the Court of Cassation against that judgment. As before the Court of Appeal, he alleged that there had been a breach of the right to a fair trial, the rights of the defence and the principle of adversarial proceedings, complaining more specifically of the use by the trial courts of evidence gathered against him even though that evidence transpired from the confidential case file, which had been brought to the attention of the defence neither during the judicial investigation nor during the investigation into the merits of the case. Finally, he criticised the Court of Appeal for dismissing his request for a face-to-face meeting with the undercover agents. 32. By judgment of 20 March 2012 the Court of Cassation dismissed the appeal on points of law. It dismissed the argument concerning access to the confidential file as follows:
“The fact that, inter alia during the investigation into the merits of the case, the defendant was not allowed to consult the confidential file does not in itself amount to a violation of Article 6 of the [Convention]. Clearly, for the defendant it constitutes a restriction of his defence rights, but that was justified by the need to protect the technical resources used and police investigatory techniques, and to guarantee the safety and anonymity of the persons implementing those techniques. That restriction of the right to adversarial proceedings is exceptional throughout the proceedings and is counterbalanced by the fact that the lawfulness of the investigative methods implemented is overseen by an independent and impartial tribunal, in this case the Indictments Division, which has discretionary power to ascertain that the content of the criminal file, including the implementation report and the [reports] on the proactive investigation, correspond to the evidence in the confidential file. Before the trial court, the defendant can also draw on the criminal file to put forward any legal arguments he may wish against the investigative methods used. The ground of appeal accordingly has no basis in law.”
33. As regards the face-to-face meeting with the undercover agents, the Court of Cassation primarily adduced the following:
“Article 6 § 3 (d) of the [Convention] secures the defendant’s right to examine or have examined witnesses against him and to obtain the attendance and examination of witnesses on his behalf; that provision does not prevent the judge from using his unfettered discretion to assess the necessity and relevance of hearing a witness who has been requested and to reject such request, unless that rejection violated the parties’ right to present evidence. The ground of appeal accordingly has no basis in law.”
34. For the remainder, the Court of Cassation held that the appellate courts had legally justified their decisions and that in adopting the reasons for the impugned judgment, particularly those concerning the alleged incitement, those courts had replied to the applicant’s specific plea relating to that matter.
... THE LAW
... II. ALLEGED VIOLATION OF ARTICLE 6 §§ 1 AND 3 (d) OF THE CONVENTION
57. The applicant complained that the proceedings had been unfair on the grounds that he had at no stage been given access to the confidential file and that he had not been allowed to examine the undercover agents or to have them examined. He relied on Article 6 §§ 1 and 3 (d) of the Convention, the relevant parts of which read as follows:
“1. In the determination of ... any criminal charge against him, everyone is entitled to a fair and public hearing ... by an independent and impartial tribunal established by law.
... 3. Everyone charged with a criminal offence has the following minimum rights:
...
d)  to examine or have examined witnesses against him and to obtain the attendance and examination of witnesses on his behalf under the same conditions as witnesses against him.”
58. The Government contested that argument. A. Non-access to the confidential file
... 2. Merits
a)  The parties’ submissions
60. The applicant raised the issue of the existence of a separate confidential file kept by the prosecution, and complained that as he had not had access to that file, he had been prevented from ascertaining whether the special investigative measures of observation and infiltration had been implemented in conformity with the principles of subsidiarity and proportionality and whether the undercover agents had had recourse to incitement. He submitted that neither the scrutiny carried out by the Indictments Division, an investigating body, of the lawfulness of the implementation of the special investigative methods, nor the inclusion in the criminal file of specific items of evidence were measures liable adequately to counterbalance those restrictions. Moreover, he complained that since the completion of that scrutiny he could no longer have complained of irregularities before the trial courts, which were bound by the Indictments Division’s decision. 61. The Government submitted that Belgian law ensured a balance between the requirements of fairness and security in conformity with the requirements of the Convention. They considered that the limitation of the rights of the defence was strictly proportional to the importance of the aims sought to be attained, that is to say combating the various forms of serious crime and protecting the identity of the undercover agent. In their view, that limitation was sufficiently offset by the safeguards surrounding the proceedings conducted before the Indictments Division.
b)  The Court’s assessment
i. Relevant general principles
62. The Court reiterates that the right to a fair trial under Article 6 § 1 is an unqualified right. However, what constitutes a fair trial cannot be the subject of a single unvarying rule but must depend on the circumstances of the particular case. When examining a complaint under Article 6 § 1, the Court must essentially ascertain whether the proceedings as a whole were fair (see, among other authorities, Taxquet v. Belgium [GC], no. 926/05, § 84, ECHR 2010; Schatschaschwili v. Germany [GC], no. 9154/10, § 101, ECHR 2015; and Ibrahim and Others v. the United Kingdom [GC], nos. 50541/08 and 3 others, § 250, ECHR 2016). 63. The general requirements of fairness contained in Article 6 apply to all criminal proceedings, irrespective of the type of offence in issue. There can be no question of watering down fair trial rights for the sole reason that the individuals in question are suspected of involvement in a criminal organisation. Nevertheless, when determining whether the proceedings as a whole have been fair the weight of the public interest in the investigation and punishment of the particular offence in issue may be taken into consideration (see, mutatis mutandis, Jalloh v. Germany [GC], no. 54810/00, § 97, ECHR 2006‑IX, and Ibrahim and Others, cited above, § 252). 64. The Court is aware of the difficulties inherent in the police’s task of searching for and gathering evidence for the purpose of detecting and investigating offences. To perform this task, they are increasingly required to make use of undercover agents, informers and covert practices. The Court has held that the use of special investigative methods – in particular, undercover techniques – cannot in itself infringe the right to a fair trial (see Ramanauskas v. Lithuania [GC], no. 74420/01, §§ 49-51, ECHR 2008). However, public interest concerns cannot justify measures which extinguish the very essence of an applicant’s defence rights (see Jalloh, cited above, § 97; Bykov v. Russia [GC], no. 4378/02, § 93, 10 March 2009; Aleksandr Zaichenko v. Russia, no. 39660/02, § 39, 18 February 2010; and Ibrahim and Others, cited above, § 252). 65. Furthermore, it should be remembered that the Court’s duty, according to Article 19 of the Convention, is to ensure the observance of the engagements undertaken by the Contracting States to the Convention. Therefore, it is not the role of the Court to determine, as a matter of principle, whether particular types of evidence may be admissible or, indeed, whether the applicant was guilty or not (see, mutatis mutandis and among other authorities, Allan v. the United Kingdom, no. 48539/99, § 42, ECHR 2002‑IX; Jalloh, cited above, § 95; Bykov, cited above, § 89; and Ibrahim and Others, cited above, § 254). While Article 6 of the Convention guarantees the right to a fair hearing, it does not lay down any rules on the admissibility of evidence as such, which is primarily a matter for regulation by national law and the domestic courts (see Gäfgen v. Germany [GC], no. 22978/05, §§ 162 and 175, ECHR 2010, and Al-Khawaja and Tahery v. the United Kingdom [GC], nos. 26766/05 and 22228/06, § 118, ECHR 2011). 66. For its part, the Court, in carrying out its task, must essentially ascertain whether the proceedings as a whole were fair (see paragraph 62 above). In making this assessment the Court looks at the proceedings as a whole, having regard to the rights of the defence but also to the interests of the public and the victims that crime is properly prosecuted and, where necessary, to the rights of witnesses (see Al-Khawaja and Tahery, cited above, § 118, and Schatschaschwili, cited above, § 101). 67. In this context the Court reiterates that it is a fundamental aspect of the right to a fair trial that criminal proceedings, including the elements of such proceedings which relate to procedure, should be adversarial and that there should be equality of arms between the prosecution and the defence. The right to an adversarial trial means, in a criminal case, that both prosecution and defence must be given the opportunity to have knowledge of and to comment on the observations filed and the evidence adduced by the other party (see Jasper v. the United Kingdom [GC], no. 27052/95, § 51, 16 February 2000; Rowe and Davis v. the United Kingdom [GC], no. 28901/95, § 60, ECHR 2000‑II; Fitt v. the United Kingdom [GC], no. 29777/96, § 44, ECHR 2000‑II; Edwards and Lewis v. the United Kingdom [GC], nos. 39647/98 and 40461/98, §§ 46 and 48, ECHR 2004‑X; and Öcalan v. Turkey [GC], no. 46221/99, § 146, ECHR 2005‑IV). In addition Article 6 § 1 requires that the prosecution authorities should disclose to the defence all material evidence in their possession for or against the accused (see Jasper, Rowe and Davis, Fitt, and Edwards and Lewis, cited above). 68. That having been said, the entitlement to disclosure of relevant evidence is not an absolute right. In any criminal proceedings there may be competing interests, such as national security or the need to protect witnesses at risk of reprisals or keep secret police methods of investigation of crime, which must be weighed against the rights of the accused. In some cases it may be necessary to withhold certain evidence from the defence so as to preserve the fundamental rights of another individual or to safeguard an important public interest. However, only such measures restricting the rights of the defence which are strictly necessary are permissible under Article 6 § 1. Moreover, in order to ensure that the accused receives a fair trial, any difficulties caused to the defence by a limitation on its rights must be sufficiently counterbalanced by the procedures followed by the judicial authorities (see Jasper, cited above, § 52; Rowe and Davis, cited above, § 61; Fitt, cited above, § 45; and Edwards and Lewis, cited above, §§ 46 and 48; see also Al‑Khawaja and Tahery, cited above, § 145).
ii. Application of those principles to the present case
69. The Court observes that the application raises the question whether, under the Belgian legal system, the holding of a separate, confidential case-file containing the authorisations and implementation reports for special investigative methods (in this case observation and infiltration) and the prohibition of the defence consulting that file throughout the proceedings – during the preliminary investigation by the public prosecutor’s office, the judicial investigation and the proceedings on the merits – is compatible with the requirements of Article 6 § 1 of the Convention and the rights of the defence in particular. 70. First of all, the Court notes from perusal of the relevant provisions of the Code of Criminal Procedure ... and as has been pointed out by the domestic courts in the present case (see paragraph 
27 above), the raison d’être of the confidential file is the need to protect the anonymity and therefore the safety of the undercover agents and to keep the methods used secret. The Court reiterates that this reason is in conformity with its case-law (see paragraph 68 above). 71. The Court further notes that Belgian legislature has confined the items of evidence that can be included in the confidential file and cannot be consulted by the parties to those liable to jeopardise the identity and safety of the persons concerned and the very use of the special investigative methods .... 72. The Court deduces that all the other information must be included in the criminal file. That file does indeed contain information regarding the implementation and the nature of the investigative methods used, the reasons for using those methods and the stages in their implementation, on the basis of which evidence the defence can rely, in the framework of adversarial proceedings, on all the available legal means of challenging the investigative methods used, including, where appropriate, resources relating to incitement. The Court holds that the latter amount to fundamental safeguards (see, to converse effect, Edwards and Lewis v. the United Kingdom, nos. 39647/98 and 40461/98, § 58, 22 July 2003, and Leas v. Estonia, no. 59577/08, § 88, 6 March 2012). 73. The applicant complained that the confidential file was kept by the Public Prosecutor’s Office. The police officer directing the observation or infiltration operation must select the items in the confidential police reports to be included in the records subsequently added to the criminal file (see paragraph Error! Reference source not found. above). 74. The Court reiterates in this connection that it has ruled contrary to Article 6 § 1 of the Convention a system in which the prosecution can, without the prior agreement or knowledge of the first-instance trial court, decide that evidence relevant to the defence is covered by public-interest immunity (see Rowe and Davis, cited above, §§ 36-37 and 63-67). It considers that unlike the latter case, where it held that the judicial review conducted by the appellate court had not been sufficient to redress the situation (ibid.), in Belgian law judicial review was conducted by the indictments division of the court of appeal, where it is called on to review the lawfulness of the implementation of special investigative methods. It remains to be seen whether that scrutiny is surrounded by adequate safeguards. 75. First of all, the Court will examine the scope of the scrutiny of the confidential file exercised by the Indictments Division. 76. In the present case, the Indictments Division of the Antwerp Court of Appeal, having consulted the confidential file, issued a judgment on 20 May 2010 ordering that the confidential documents on the proactive investigation be added to that file, and that certain pieces of evidence concerning that investigation be added to the opened criminal file. As a result, the public prosecutor’s decisions of 18 September 2008 confirming the existence of observation and infiltration authorisations and of the 25 September 2008 record concerning those authorisations were added to the criminal file (see paragraph .
18 above). In the end the Indictments Division decided, by judgment of 24 June 2010, that, in the framework of the review set out in Articles 235bis and 235ter CIC, the criminal file was complete, that no nullity, irregularity or violation of legal or Convention provisions had been found and that no irregularities had been committed in implementing the special investigative methods (see paragraph 19 above). 77. The applicant submitted that the review thus conducted had not allowed any court to assess the necessity or advisability of disclosing the information contained in the confidential file to the defence. 78. However, the Court notes that in the instant case the Indictments Division held, in its judgment of 24 June 2010, that the criminal file was complete. It had therefore been able to assess whether material in the confidential file, more particularly material which was not such as to jeopardise the technical resources and police investigation techniques used or the protection of the safety and anonymity of the police officers responsible for conducting the observation or infiltration operation, should not be included in the criminal file, whereas no such material was present in the latter file. The investigating body therefore had at its disposal all the necessary evidence to conclude, independently and impartially, that the criminal file, which included the implementation report and the non-confidential material relating to the proactive investigation, corresponded to the contents of the confidential file (see, to converse effect, Baltiņš v. Latvia, no. 25282/07, § 63, 8 January 2013). 79. Having regard to the foregoing considerations, the Court considers that the review conducted by the Indictments Division, an independent and impartial judicial body, of the completeness of the criminal file, and therefore, indirectly, of the need to withhold the information included in the confidential file from the defence, constitutes an important safeguard (see, mutatis mutandis, Jasper, cited above, § 56, and Fitt, cited above, § 49). 80. Furthermore, as regards, in particular, the applicant’s alleged inability to verify whether the undercover agents had engaged in incitement, the Court reiterates that Article 6 § 1 prohibits police incitement and that the public interest cannot justify the use of evidence gathered by means of such incitement. The principles relating to police incitement were summarised in the aforementioned Ramanauskas judgment (§§ 49-61). The criteria developed by the Court throughout its case-law to differentiate between incitement in breach of Article 6 § 1 and the legitimate use of special investigative techniques are summarised in the Bannikova v. Russia judgment (no. 18757/06, §§ 37-65, 4 November 2010). 81. The Court sees no need in the present case to go into a detailed analysis of those criteria. It is clear that in the domestic courts the applicant pleaded incitement but failed in any way to substantiate his allegations with factual evidence such as to convince the courts that he might have been the victim of incitement. In those circumstances, the Court is not persuaded that the situation under scrutiny falls within the category of cases of incitement (see, mutatis mutandis, Trifontsov v. Russia (dec.), no. 12025/02, § 32, 9 October 2012, and Lyubchenko v. Ukraine (dec.), no. 34640/05, § 33, 31 May 2016). Furthermore, the summary nature of the applicant’s line of defence did not prevent the courts from conducting scrutiny and assessing the facts of the case from the incitement angle in order to dismiss the said allegations on the basis of evidence contained in the criminal file (see paragraphs 28, 29 and 34 above). 82. Finally, and this is at least equally important in the Court’s view, the Court of Cassation pointed out in its 20 March 2012 judgment in the applicant’s case that the documents in the confidential file could not be used in evidence against the defendant (see paragraph 32 above). In fact, in the instant case, the Indictments Division noted from the reports included in the criminal file that on 17 September 2008 sufficiently cogent circumstantial evidence concerning the charges against the applicant had been gathered to instigate a proactive investigation. That circumstantial evidence had then been reflected in the public prosecutor’s written conclusions, which were included in the criminal file (see paragraph 19 above). 83. Having regard to the foregoing considerations, the Court sees no need to go further into the applicant’s complaint that during the investigation into the merits of the case neither he himself nor the trial courts were able to consult the confidential file. Indeed, it agrees with the Court of Cassation (see paragraph 32 above) that the ab initio restriction of the defence rights was justified and was adequately counterbalanced by the prior review procedure conducted by an independent and impartial tribunal, that is to say the Indictments Division. 84. B. The applicant’s inability to question the undercover agents or to have them questioned
... 2. Merits
a)  The parties’ submissions
86. The applicant complained that the undercover agents had at no stage been heard by the investigating bodies or the trial courts and that there had been no face-to-face meeting with those agents, which had prevented him from verifying their reliability and ascertaining whether they had in fact engaged in incitement. He presented that complaint as a “circumstance aggravating” the first complaint in that the denial of a face-to-face meeting had worsened the difficulties already caused to the defence by its lack of access to the confidential file. 87. The Government submitted that face-to-face meetings were prohibited in order to protect the identities and the safety of the police officers responsible for the investigation. That prohibition was offset by the verification of lawfulness carried out by the Indictments Division. The latter drew on the confidential file to check the identities and the reliability of the undercover agents, thus verifying whether the case had involved any incitement, and if so, deciding on the lawfulness of the evidence. At all stages in the proceedings before the investigating authority the defendants had had the opportunity of consulting the opened case file, which had necessarily contained all the relevant evidence. In addition, throughout the proceedings in the instant case the domestic courts had sought to ensure that the defence rights and the fairness of proceedings were being respected, in compliance with the requirements of Article 6 of the Convention.
b)  The Court’s assessment
i. Relevant general principles
88. The Court reiterates that the guarantees in paragraph 3 (d) of Article 6 are specific aspects of the right to a fair hearing set forth in paragraph 1 of this provision (see Al-Khawaja and Tahery, cited above, § 118). It will therefore consider the applicant’s complaint under both provisions taken together (see Schatschaschwili, cited above, § 100). Moreover, when examining a complaint under Article 6 § 1, the Court must essentially ascertain whether the proceedings as a whole were fair (see paragraph 62 above). In making this assessment it will look at the proceedings as a whole, having regard to the rights of the defence but also to the interests of the public and the victims that crime is properly prosecuted and, where necessary, to the rights of witnesses (ibid.). The Court also reiterates in that context that the admissibility of evidence as such is a matter for regulation by national law and the domestic courts, and that its only task is to determine whether the proceedings were fair (see paragraphs 65 and 66 above). 89. The Court further reiterates that Article 6 § 3 (d) enshrines the principle that, before an accused can be convicted, all evidence against him must normally be produced in his presence at a public hearing with a view to adversarial argument. Exceptions to this principle are possible but must not infringe the rights of the defence, which, as a rule, require that the accused should be given an adequate and proper opportunity to challenge and question a witness against him, either when that witness makes his statement or at a later stage of proceedings (see Al-Khawaja and Tahery, cited above, § 118 and the references therein, and Schatschaschwili, cited above, §§ 103-105). 90. However, Article 6 § 3 (d) does not confer an absolute right on the defendant to call witnesses. It is normally for the national courts to decide whether it is necessary or advisable to call a witness (see, among other authorities, Bricmont v. Belgium, 7 July 1989, § 89, Series A no. 158; S.N. v. Sweden, no. 34209/96, § 44, ECHR 2002‑V; and Przydział v. Poland, no. 15487/08, § 46, 24 May 2016). 91. Moreover, in its judgment in Al-Khawaja and Tahery the Court concluded that the admission as evidence of the statement of a witness who had been absent from the trial and whose pre-trial statement was the sole or decisive evidence against the defendant did not automatically result in a breach of Article 6 § 1. The Court pointed out that the admission of the evidence of absent witnesses, because of the inherent risks for the fairness of the trial, constituted a very important factor to balance in the scales in assessing the overall fairness of the proceedings (ibid., §§ 146 and 147). 92. According to the principles established in the Al-Khawaja and Tahery judgment and reiterated in Schatschaschwili (cited above, § 107), examination of the compatibility with Article 6 §§ 1 and 3 (d) of the Convention of proceedings in which statements made by a witness who was not present and questioned at the trial are used as evidence comprises three stages (see Al‑Khawaja and Tahery, cited above, § 152). The Court must examine
(i) whether there was a good reason for the non-attendance of the witness and, consequently, for the admission of the absent witness’s untested statements as evidence (ibid., §§ 119-25);
(ii) whether the evidence of the absent witness was the sole or decisive basis for the defendant’s conviction (ibid., §§ 119 and 126-47); and
(iii) whether there were sufficient counterbalancing factors, including strong procedural safeguards, to compensate for the handicaps under which the defence laboured as a result of the admission of the untested evidence and to ensure that the trial, judged as a whole, was fair (ibid., § 147). 93. Nevertheless, the lack of a good reason for a witness’s absence alone cannot render a trial unfair, but was a very important factor to be weighed in the balance when assessing the overall fairness of a trial, and one which could tip the balance in favour of finding a breach of Article 6 §§ 1 and 3 (d) (see Schatschaschwili, cited above, § 113). 94. The Court must also review the existence of sufficient counterbalancing factors not only in cases where, following its assessment of the domestic courts’ evaluation of the weight of the evidence, it finds it unclear whether the evidence in question was the sole or decisive basis but is nevertheless satisfied that it carried significant weight and that its admission may have handicapped the defence. The extent of the counterbalancing factors necessary in order for a trial to be considered fair will depend on the weight of the evidence of the absent witness. The more important that evidence, the more weight the counterbalancing factors will have to carry in order for the proceedings as a whole to be considered fair (ibid., § 116). 95. In the Court’s view, the same principles are applicable in the present case, where the undercover agents may be considered as prosecution witnesses.
ii. Application of those principles to the present case
α. Reasons for not allowing the applicant to question or have questioned the undercover agents
96. The Court notes that despite the applicant’s repeated requests for a face-to-face meeting with the police officers who had acted as undercover agents with a view to their questioning, they were heard by the domestic courts neither during the preliminary stage of the investigation nor during the proceedings before the trial courts. By judgment of 16 March 2011, the Hasselt Court of First Instance dismissed the applicant’s request for a face-to-face meeting, primarily on the grounds that in view of a number of circumstances it was unnecessary for the establishment of the truth, the exercise of the defence rights and the safeguard on a fair trial for the agents to be heard (see paragraph 
27 above). 97. The Court understands that the domestic court considered that questioning the undercover agents was neither necessary nor useful for the establishment of the truth. As it has pointed out previously (see paragraph 90), it is for the national courts to decide whether it is necessary or advisable to call a witness. 98. Nonetheless, the Court considers that in the instant case, having regard to the fact that the defence on several occasions requested a hearing of the undercover agents and that the latter’s witness statements played a role in the applicant’s conviction (see paragraphs 104-105 below), it is hard to see the fact of questioning them as having been completely unnecessary from his point of view. Further thought should therefore be given to whether the refusal to question the undercover agents was compatible with Article 6 §§ 1 and 3 (d). 99. As regards the reasons given by the domestic courts for their refusal to question the undercover agents, the Court notes that, in addition to the fact that it did not deem such questioning necessary (see paragraph 96 above), the court of first instance considered that the undercover agents’ safety and the importance of their anonymity with a view to their involvement in future cases militated against a face-to-face meeting, especially since in the instant case the infiltration had covered several years and that bonds of friendship had grown up between the agents and several of the defendants and their partners. Lastly, the court noted that the defence had not specified what questions it wished to put to the undercover agents and that, as regards the only question mentioned, it had already been answered by other evidence in the case-file (see paragraph 
27 above). This reasoning was upheld by the Antwerp Court of Appeal in its 13 October 2011 judgment, which added that the truth and the identity of the guilty party had also been established on the basis of other evidence and that the request for a face-to-face meeting had been rather moot (see paragraph 30 above). 100. The Court has already held that allowing undercover police agents to provide information anonymously is a vital tool in prosecuting, in particular, organised crime (see, in a case concerning police informers, Donohoe v. Ireland, no. 19165/08, § 80, 12 December 2013). However, it has also emphasised that the balancing of the interests of the defence against arguments in favour of maintaining the anonymity of witnesses raises special problems if the witnesses in question are members of the police force of the State. Although their interests - and indeed those of their families - also deserve protection under the Convention, it must be recognised that their position is to some extent different from that of a disinterested witness or a victim.

Article of the Convention at issue: Article 6
Outcome: no_violation