Opinion of the Advocate General — ECLI:EU:C:2026:204
Date: 2026-03-12
Language of the case: French

Provisional text OPINION OF ADVOCATE GENERAL RICHARD DE LA TOUR delivered on 12 March 2026 (1) Case C‑559/23 P International Management Group (IMG) v European Commission ( Appeal – Objection that the appeal is inadmissible because the action for non-contractual liability is time-barred – Failure by the General Court to rule on the plea of inadmissibility prior to dismissing the action as unfounded – External investigation by the European Anti-Fraud Office (OLAF) – Communication of OLAF’s investigation report to the national judicial authorities – Unauthorised disclosure of the investigation report to the press – Material and non-material damage allegedly suffered by the appellant – Causal link – Event giving rise to the damage capable of being attributed either to the European Union or to the national authorities concerned – Uncertainty – Burden of proof ) I. Introduction 1. The present appeal has been brought against the judgment of the General Court of the European Union of 28 June 2023, IMG v Commission, (2) by which the General Court dismissed as unfounded the action seeking to establish the non-contractual liability of the European Union, brought by International Management Group (IMG), on account of the unauthorised disclosure to the press of an investigation report concerning it, drawn up by the European Anti-Fraud Office (OLAF). 2. When examining the appeal, the Court of Justice will, inter alia, have to validate or censure the position of the General Court which, in the judgment under appeal, held that it was necessary to exclude the non-contractual liability of the European Union on account of uncertainty as to the perpetrator of the event giving rise to the damage, ‘in the absence of evidence to that effect’, (3) since that damage could have been caused either by a source internal to the European Union, namely OLAF or the European Commission, or by a source external to it, namely the national judicial authorities concerned. 3. In the present Opinion, I shall propose that the Court of Justice set aside the judgment under appeal on the ground that the General Court failed to comply with the rules on the burden of proof and the taking of evidence in its assessment of an alleged breach by the Commission and OLAF of their obligation of confidentiality. I shall set out the reasons why such an error of law also vitiates its finding relating to an alleged breach by those parties of their duty to act diligently. II. Factual background 4. The background to the dispute is set out in paragraphs 2 to 12 of the judgment under appeal. 5. IMG was established, according to its articles of association, as an international organisation. As part of its activities, it has concluded a number of agreements with the Commission, in application, inter alia, of the ‘indirect or joint management’ method of implementing the EU budget provided for in the EU financial rules. 6. The Director-General of OLAF opened an external investigation into the legal status of the appellant. (4) At the end of that investigation, OLAF considered, in essence, in its final investigation report (‘the OLAF report’), drawn up on 9 December 2014, that IMG could not be regarded as an ‘international organisation’ within the meaning of the EU financial regulations, and recommended that the Commission impose administrative and financial penalties on IMG and take steps to recover the sums paid to it in that capacity. 7. The OLAF report was officially sent on 12 December 2014 to the Commission and to the French and Belgian judicial authorities. On 13 February 2015, the information regarding the content of that report was published in the magazine Der Spiegel. On 18 February 2015, the appellant sent OLAF a letter reporting a possible leak of information to the press relating to the content of the report. 8. On 13 March 2015, the Director-General of OLAF sent a letter to the President of the European Parliament stating that he had been informed that the OLAF report had been circulated within Parliament’s Committee on Budgetary Control. In that letter, the Director-General of OLAF recalled that the report had not been officially disclosed to Parliament and asked the President of that institution to take the necessary measures to put an end to the circulation of the document. 9. By letter of 20 March 2015, OLAF replied to the appellant that its report had been sent exclusively to the competent national authorities and to the Secretariat-General of the Commission. 10. On 11 December 2015, the OLAF report was published, without its annexes, on the website of the newspaper New Europe. The appellant was informed that two investigations had then been opened by the Secretary-General of the Commission and by OLAF in order to identify the source of the leak. 11. On 30 January 2017, the Secretary-General of the Commission sent a letter to the appellant informing it that the investigations had been closed and that they had been unable to identify the source of the leak. 12. On 5 June 2018, the appellant obtained a copy of the OLAF report and its annexes. III. Proceedings before the Courts of the European Union A. The procedure before the General Court and the judgment under appeal 13. By application lodged with the Registry of the General Court on 21 December 2020, the appellant brought an action under Article 268 TFEU seeking compensation for the material and non-material damage which it claims to have suffered as a result of the unlawfulness of the conduct of the Commission and of OLAF following the latter’s report. By the judgment under appeal, the General Court dismissed the action in its entirety. B. Procedure before the Court of Justice and forms of order sought 14. On 7 September 2023, the appellant lodged an appeal against the judgment under appeal. In the form of order sought, it asks the Court of Justice to set aside that judgment, to grant the form of order sought before the General Court, to rule that the Commission has incurred non-contractual liability, to order the Commission to pay compensation for the damage sustained by the appellant, valued, subject to any adjustment, at EUR 10 000 per month for a period beginning in mid-December 2015 and running until delivery of the judgment to be given, in respect of the non-material damage, and at EUR 2.1 million in respect of the material damage, to be increased by late payment interest, and to order the Commission to pay all the costs at first instance and on appeal. 15. The Commission asks the Court of Justice to dismiss the appeal as inadmissible or, in the alternative, as unfounded and to order the appellant to pay the costs. IV. Analysis 16. In support of its appeal, the appellant relies on five grounds of appeal alleging, first, an error in the assessment of the causal link on which the non-contractual liability of the European Union depends; second, an error in the assessment of the condition relating to the imputability of the harmful event to OLAF or the Commission; third, an error in the assessment of the existence of illegality based on a breach of the duty to have regard to the welfare of officials; fourth, an error in the assessment of the existence of illegality based on a breach of the duty to act diligently; and, lastly, fifth, errors of law affecting the General Court’s assessment relating to the removal of the opinion of the Commission’s Legal Service from the file. 17. For its part, the Commission claims, primarily, that the appellant’s action for damages was already time-barred when it was lodged, with the result that the appeal is inadmissible. In the alternative, the Commission submits that the appeal should be dismissed as unfounded. A. Admissibility of the appeal 18. The present appeal raises two difficulties as to its admissibility. 1. IMG’s capacity to bring an action for non-contractual liability against the European Union 19. In the judgment in IMG v Commission (C‑790/24 P), in which I am also delivering an Opinion today, the Court of Justice is called upon to rule on the appeal brought against the judgment of 4 September 2024, IMG v Commission, (5) in which the General Court upheld the legality of the Commission’s decision of 8 June 2021 refusing to accord the appellant, with retroactive effect from 16 December 2014, the status of an international organisation. 20. In the event that, at the end of its examination, the Courts of the European Union decide to confirm the legality of that decision, I consider that that circumstance is not capable of affecting the admissibility of the present action for damages, brought on 21 December 2020, on the ground that IMG lost its capacity to bring legal proceedings on the date on which the EU judicature is called upon to rule. 21. It is apparent from the case-law of the Court that the concept of ‘legal person’ implies, in principle, the existence of a legal personality constituted under the law of a Member State or third country and capacity to be a party to legal proceedings under that law. (6) 22. However, even if IMG had not been established as an international organisation or had lost that status, the fact that it is not or is no longer a subject of international law does not deprive it of its status as a legal person in the legal system of one or more States or of its capacity to be a party to legal proceedings. Moreover, the Commission did not dispute that capacity in response to a question put to it by the Court at the hearing. IMG has an internal structure (budget, staff and infrastructure) which ensures it the necessary autonomy to act as a responsible entity in legal matters, and its articles of association, like the provisions of the headquarters agreements it has concluded with various States, recognise IMG’s capacity to be a party to legal proceedings in the national legal system. 23. In the present case, the appellant’s situation is similar to that referred to in the case which gave rise to the judgment of 28 October 1982, Groupement des Agences de voyages v Commission, (7) since the appellant was entrusted with budget implementation tasks by the Commission under the indirect management method with an ‘international organisation’ for several years, with the result that it was regarded, during that period, as having that status. I would add that, before the Courts of the European Union, the Commission treated IMG as a legal person with the capacity to be a party to legal proceedings, since it did not raise any objection of inadmissibility in that regard during a period when 13 proceedings were brought before the Courts of the European Union. Nor did the EU judicature find that the appellant lacked capacity to act, even though that is a legal ground that is absolute. 24. I would add that, in paragraph 112 of the judgment of 18 January 2007, PKK and KNK v Council, (8) which concerned, inter alia, the Kurdistan Workers’ Party (PKK), the Court held that, since the EU legislature considers that an organisation whose existence is called into question retains an existence sufficient for it to be subject to restrictive measures, it must be accepted, on grounds of consistency and justice, that that entity continues to have an existence sufficient to contest that measure. The effect of any other assessment would be that an organisation could be included in the list at issue without being able to bring an action challenging its inclusion. 25. Similarly, if one considers that OLAF and the Commission were required to ensure the confidentiality of the findings of the OLAF report, the requirements of consistency and the necessary respect for the right to effective judicial protection require that the appellant be recognised as having sufficient existence to seek compensation for the damage it claims to have suffered as a result of the unauthorised disclosure of those findings to the press. (9) 26. For all those reasons, I consider that IMG has the capacity to bring an action for a declaration as to the non-contractual liability of the European Union, irrespective of the conclusions that the Courts of the European Union decide to reach as regards its status as an international organisation. 2. Decision of the General Court to rule on the substance of the action without ruling on the limitation period for the action for damages 27. In its response, the Commission argues that the appeal is inadmissible on the ground that the action for damages brought by IMG is time-barred for the reasons it set out in its plea of inadmissibility raised before the General Court. 28. In the first place, the Commission submits that the limitation period expired on 11 December 2020, that is to say, five years after the OLAF report was published on the website of the newspaper New Europe, whereas the appellant’s action was brought on 21 December 2020, that is to say, 10 days later. In that regard, the Commission recalls that, in accordance with the case-law, extensions on account of distance do not apply to limitation periods, which are periods governed by substantive law. 29. In the second place, the Commission argues that the starting point of the limitation period predates that publication. The damage alleged by the appellant materialised, at the latest, when the OLAF report was leaked. The unlawful acts alleged by IMG related to the question of its legal status, and it was informed well before 11 December 2015 of the doubts harboured in that regard by OLAF and the Commission. 30. The appellant disputes that assessment. First, it points out that the Commission neither lodged a cross-appeal nor raised a plea of inadmissibility. Second, it submits that the damage for which it seeks compensation is ongoing damage, which materialised at the earliest at the time when the OLAF report was disclosed without authorisation. In that regard, it states that it did not have the opportunity to acquaint itself with that report before its disclosure, since that report was communicated to it in June 2018 before the hearing held on 27 September 2018 in the joined cases which gave rise to the judgment of 31 January 2019, International Management Group v Commission. (10) 31. It is clear from the Court’s case-law that limitation constitutes an objection to admissibility which, unlike procedural time limits, is not absolute, but extinguishes the action for damages solely at the request of the defendant, since compliance with a limitation period cannot be raised by a Court of the European Union of its own motion but must be raised by the party concerned. (11) 32. In the present case, it is apparent from paragraph 22 of the judgment under appeal that the Commission had asked the General Court to dismiss the appellant’s action as inadmissible, on the ground that it was time-barred. However, after recalling, in paragraph 23 of that judgment, the case-law according to which the Courts of the European Union are entitled to assess, according to the circumstances of each case, whether the proper administration of justice justifies the dismissal of the action on the merits without a prior ruling on its admissibility, the General Court decided, in paragraph 24 of that judgment, to examine the merits of the appellant’s claim for damages, without first ruling on the plea of inadmissibility alleging that its action was time-barred. (12) The Commission therefore invites the Court of Justice to examine whether the appellant’s action for damages is time-barred. 33. Like the solution adopted in a similar situation in the judgments of 25 March 2010, Sviluppo Italia Basilicata v Commission, (13) and of 24 March 2022, GVN v Commission, (14) the line of argument put forward by the Commission must be regarded as not seeking to call into question the admissibility of the present appeal. Such an approach would not, in any event, be practicable, since the General Court dismissed the action as unfounded, and the appellant, which had been unsuccessful in its submissions, brought an appeal against the judgment under appeal, as it was entitled to do under the second paragraph of Article 56 of the Statute of the Court of Justice of the European Union. 34. The Commission’s argument must be regarded as seeking to challenge the General Court’s decision to dismiss the action on the merits without ruling on the ground of inadmissibility that it had raised. 35. The Court of Justice holds that it is for the General Court to assess whether the proper administration of justice justifies the dismissal of an action on the merits without ruling on the grounds of inadmissibility raised, in the present case by the Commission, and considers, moreover, that such an assessment cannot be regarded as adversely affecting the Commission. Therefore, contrary to the appellant’s contention, it was not able to bring a cross-appeal. (15) 36. Thus, in paragraph 24 of the judgment under appeal, the General Court held, in the interests of procedural economy, that it was not necessary to give a prior ruling on the plea of inadmissibility alleging that the action was time-barred, before examining the merits of the appellant’s claim for compensation. 37. In so far as the Commission’s line of argument relating to the limitation period for the appellant’s claim for compensation does not seek to call into question the operative part of the judgment under appeal, it must be regarded, as it stands, as ineffective and, accordingly, may be rejected as such. (16) B. Substance 38. It follows from the settled case-law of the Court of Justice that in order for the European Union to incur non-contractual liability under the second paragraph of Article 340 TFEU, it is necessary to establish the following: – the existence of a sufficiently serious breach of a rule of law intended to confer rights on individuals; – the fact of damage; and – the existence of a direct causal link between the breach of the obligation resting on the author of the act and the damage sustained by the injured party. (17) 39. It is also apparent from that case-law that, if any one of those conditions is not satisfied, the action must be dismissed in its entirety and it is unnecessary to consider the other conditions for non-contractual liability on the part of European Union. In accordance with that case-law, the Courts of the European Union are not required to examine those conditions in any particular order. (18) 40. In the judgment under appeal, the General Court held, first, that there may be a causal link between, first, the breach of the obligation of confidentiality and the duties to act diligently and to have regard for the welfare of officials and, second, the damage allegedly suffered by the appellant, ruling out the possibility of such a link with the alleged irregularities affecting the opening, conduct or findings of the investigation, which the appellant also relied on (paragraph 42 of the judgment under appeal). 41. Second, the General Court held that the European Union cannot be held liable either for the alleged breach of the obligation of confidentiality, because there is uncertainty as to the origin of the leak (paragraph 67 of the judgment under appeal), or for the breach of the duty to have regard for the welfare of officials, on the ground that it is not applicable in the present case (paragraph 73 of the judgment), or for breach of the duty to act diligently, because that duty did not impose on the Commission an obligation to condemn the leak to the press of information relating to OLAF’s investigation and to distance itself from the information published, since responsibility for the leak could not be attributed to the Commission (paragraph 92 of the judgment under appeal). 42. The General Court therefore dismissed the appellant’s action. 1. The first ground of appeal, alleging incorrect assessment of the causal link on which the non-contractual liability of the European Union depends 43. By its first ground of appeal, the appellant challenges paragraphs 37 to 42 of the judgment under appeal, in which the General Court looked for the existence of a sufficiently direct causal link between the unlawful conduct of OLAF relied on by the appellant and the damage the appellant allegedly suffered. (a) The judgment under appeal 44. For the reasons set out in paragraphs 37 to 39 of the judgment under appeal, the General Court found that the first three instances of illegality relied on by the appellant, relating to OLAF’s competence, the content of its report and the lawfulness of its investigation, did not have a sufficiently direct link with the damage allegedly suffered by the appellant. 45. By contrast, as regards the fourth instance of illegality, the General Court found, in paragraph 40 of the judgment under appeal, that it concerns the breach, by OLAF and the Commission, of their obligation of confidentiality, as well as the breach by the Commission of its duty to act diligently and its duty to have regard for the welfare of officials following the leak of the OLAF report to the press. The General Court held, in paragraph 41 of the judgment, that the fact that, as a result of the leak, the appellant’s usual partners and donors became aware of the confidential information contained in that report was such as to have raised doubts in their minds as to the appellant’s honesty, legal capacity and legal personality and, therefore, to have caused the appellant the damage for which it sought compensation. 46. Consequently, the General Court found that the existence of a sufficiently direct causal link between the fourth instance of illegality alleged by the appellant and that damage had been established. Therefore, as is apparent from paragraph 42 of the judgment under appeal, the General Court decided to examine the lawfulness of the conduct alleged against the Commission and OLAF, solely as regards the obligation of confidentiality, the duty to act diligently and the duty to have regard for the welfare of officials. (b) The parties’ arguments 47. The first ground of appeal consists of two parts. 48. By the first part of the first ground of appeal, the appellant submits that, by ruling out the existence of a direct causal link between, on the one hand, the first three irregularities vitiating the content of the OLAF report on which it had relied, namely the illegalities vitiating the opening of the investigation, the conduct of the investigation and the drafting of the report, and, on the other hand, the damage it claims to have suffered, the General Court ruled infra petita. 49. By the second part of that ground of appeal, the appellant disputes the General Court’s assessment in paragraph 42 of the judgment under appeal, according to which the condition relating to the causal link on which the European Union’s liability depends is satisfied solely in relation to the alleged breach of the obligation of confidentiality, the duty to act diligently and the duty to have regard for the welfare of officials, following the leak of the OLAF report to the press. The appellant submits that the damage which it has suffered results not only from the disclosure of the report to the press but also from a set of inseparable circumstances that marred the opening of the investigation, the conduct of that investigation and the drafting of the conclusions relating thereto, without which the alleged damage would not have occurred. 50. The Commission maintains that the first ground of appeal is unfounded. In particular, it argues that the criticisms made by the appellant regarding the taking into account of the first three instances of illegality allegedly vitiating the OLAF report are the subject of an action for annulment which is subject to its own limitation periods. (c) Assessment (1) The first part of the first ground of appeal, alleging that the General Court ruled infra petita 51. I propose, at the outset, that the Court of Justice reject the first part of the first ground of appeal as unfounded. 52. In paragraphs 37 to 39 of the judgment under appeal, the General Court set out, with reasons, why a sufficiently direct causal link could not be established between, on the one hand, the conduct of which OLAF is accused as regards the conditions for opening its investigation, the conduct of that investigation and the drafting of the report and, on the other hand, the damage claimed by IMG. 53. First, as regards OLAF’s lack of competence to open its investigation (first instance of illegality), the General Court noted, in paragraph 37 of its judgment, that the decision to open an investigation is not public and held that that failure does not have a sufficiently direct link with the damage claimed by the appellant. 54. Second, as regards the misinterpretation of the concept of ‘international organisation’ (second instance of illegality) and the infringement by OLAF of the rules and principles governing the conduct of its investigation (third instance of illegality), the General Court held, in paragraph 39 of the judgment, that those instances of illegality relate to the conduct of the investigation and the drafting of the report. It noted that, since OLAF reports are, in principle, confidential, they can cause damage only indirectly, following the adoption of a decision by the Commission or by a national authority, after the report’s transmission, which is based on its content, and held that such instances of illegality are unrelated to the leak of the OLAF report to the press. 55. Consequently, by holding that the first three instances of illegality relied on by IMG do not have a sufficiently direct link with the damage allegedly suffered by the appellant, the General Court did not, in my view, commit the irregularity relied on in support of the first part of the first ground of appeal. (2) The second part of the first ground of appeal, alleging incorrect assessment of the existence of a causal link 56. In my view, the General Court did not err in law in concluding, in paragraph 42 of the judgment under appeal, that the damage alleged was caused solely by the disclosure of the OLAF report to the press, with the exception of the irregularities which affected the content of the report. 57. Legal causality refers, strictly speaking, to the relationship between two events, namely the act that gives rise to the damage and the damage itself. (19) As academic writers point out, a number of facts and events usually precede the occurrence of damage. The Courts of the European Union are then called upon to determine which of those facts or events will be regarded as legally the cause of the damage. (20) To that end, there are two theories, namely that of adequate causation and that of equivalence of conditions. 58. According to the theory of equivalence of conditions, any event that was indispensable to the occurrence of the damage must be regarded as a legal cause of that damage. On the other hand, according to the doctrine of adequate causation, not all events which participated in the occurrence of the damage necessarily constitute its legal cause. Only events that would normally produce the harmful result in the usual course of events and depending on conduct adopted can be considered to be causes. (21) 59. According to settled case-law on establishing the causal link laid down in the second paragraph of Article 340 TFEU, which the Court recalled in paragraphs 148 to 152 of the judgment of 18 December 2025, WS and Others v Frontex (Joint return operation), (22) the European Union cannot be required to make good every harmful consequence, even a remote one, of an unlawful act. (23) The Court of Justice thus requires it to be established that there is a sufficiently direct causal nexus between the conduct of the EU’s institutions and the damage, as the General Court rightly pointed out in paragraph 33 of the judgment under appeal. (24) Furthermore, it is not enough that the conduct complained of is one of the causes of the alleged damage or that it was the necessary condition for the occurrence of that damage. It is also necessary to show that the conduct complained of is the determining cause of the alleged damage. (25) According to academic writers, the damage must be in an ‘immediate and foreseeable’ causal relationship with the conduct at issue. (26) The Court’s case-law therefore seems to be based more on the doctrine of adequate causation. 60. In the present case, it is common ground that the origin of the damage allegedly suffered by IMG lay in several causes, linked to the information, conclusions and recommendations set out in the OLAF report and the unauthorised disclosure of that report to the press. Nevertheless, not all of those causes contributed in a sufficiently direct manner to the occurrence of that damage. Thus, although the errors allegedly committed by OLAF in the course of the investigation may have contributed to the occurrence of the damage alleged by IMG, they do not constitute the ‘determining cause’. According to the normal and foreseeable course of events, only the disclosure of that report to the press could, with the greatest possible certainty, have caused the damage allegedly suffered by IMG, (27) and the General Court ruled, to that effect, in its judgment of 12 September 2007, Nikolaou v Commission. (28) In the absence of disclosure to the press of the content of the OLAF report, the damage claimed by the appellant would not have occurred. In accordance with the premiss on which the General Court’s analysis is based, reports drawn up by OLAF are confidential. Thus, I agree with the General Court’s consideration in paragraph 38 of the judgment under appeal that if the second and third instances of illegality relied on by the appellant, relating to a misinterpretation of the concept of ‘international organisation’ and the infringement of several procedural rules, affected, respectively, the content of the OLAF report and the lawfulness of the investigation conducted by OLAF, those instances of illegality are, nonetheless, unrelated to the leak of the OLAF report to the press. 61. In the light of all the foregoing, I propose that the Court of Justice reject the first ground of appeal as unfounded. 2. The second ground of appeal, alleging incorrect assessment of the condition relating to the imputability of the harmful event to OLAF or the Commission 62. By its second ground of appeal, the appellant disputes the reasoning set out in paragraphs 47 to 69 of the judgment under appeal, at the end of which the General Court concluded that the first condition for the European Union to incur non-contractual liability was not satisfied on the ground that the unlawfulness of the conduct of the European Union, consisting of the breach of its obligation of confidentiality, could not be imputed to it because of the uncertainty as to the origin of the leak. (a) The judgment under appeal 63. After noting, in paragraph 48 of the judgment under appeal, the principle that it is for the appellant to establish that the conditions giving rise to the non-contractual liability of the European Union have been satisfied, the General Court nevertheless pointed out, in paragraph 49 of the judgment under appeal, that there is a qualification of that principle. Referring to the judgments of 8 July 2008, Franchet and Byk v Commission, (29) and of 11 July 2019, BP v FRA, (30) it thus recalled that, where a harmful event may have been the result of a number of different causes and the EU institution has adduced no evidence enabling it to be established to which of those causes the event was imputable, although it was best placed to provide evidence in that respect, the uncertainty which remains must be construed against it. 64. It is in the light of those considerations that, in paragraphs 50 to 68 of the judgment under appeal, the General Court examined the extent to which the breach of the obligation of confidentiality resulting from the leak of the OLAF report, on 13 February 2015, to the magazine Der Spiegel, and then, on 11 December 2015, on the website of the newspaper New Europe, could be imputed to the Commission or OLAF. 65. In paragraph 62 of the judgment under appeal, the General Court held that such a qualification of the burden of proof rule was not applicable in the present case since, on the date of the first leak to the press, namely 13 February 2015, the Commission and OLAF were no longer the only institutions in possession of the latter’s report since it had been lawfully sent, on 12 December 2014, pursuant to Article 11(3) of Regulation (EU, Euratom) No 883/2013, (31) to the Belgian and French judicial authorities. The General Court concluded that the Commission could not be regarded as being best placed to provide evidence to establish the cause of the leak, and the damage it allegedly caused. 66. In paragraphs 64 and 65 of the judgment under appeal, the General Court also distinguished the facts in the present case from those in the case that gave rise to the judgment of 8 July 2008, Franchet and Byk v Commission. (32) The General Court pointed out that, although in that case there were several possible causes of the leaks at issue (since both the Commission and the French judicial authorities were in possession of the confidential information concerned), it should be noted that the Commission had not raised before the General Court the possibility that the source could have been outside the EU institutions. However, the General Court noted in paragraphs 56 and 65 of the judgment under appeal that the Commission raised such a possibility in the present case. 67. In paragraph 66 of the judgment under appeal, the General Court also noted that neither the conclusions of the European Ombudsman set out in Decision 220/2015/ANA of 14 December 2017 nor the internal investigation conducted by the Commission had been able to identify the origin of the leak. 68. As a result of those factors, in paragraph 67 of the judgment the General Court concluded that ‘the uncertainty as to the source of the leak cannot lead, in the absence of evidence to that effect, to the Commission and OLAF being held responsible for it’. (33) The General Court therefore ruled, in paragraph 68 of the judgment under appeal, that the alleged breach of the obligation of confidentiality cannot be imputed to the European Union and that there was no need to examine whether that breach constituted a sufficiently serious breach of a rule of law intended to confer rights on individuals. (b) Arguments of the parties 69. The second ground of appeal consists of three parts. 70. In the first place, the appellant submits that the qualification of the rule on the burden of proof incumbent on the appellant, to which the General Court refers in paragraph 49 of the judgment under appeal, requires the defendant institution to provide an explanation or a credible hypothesis as to the circumstances in which a leak may have occurred. A mere reference by that institution to the possibility that the illegality giving rise to the origin of a leak may have been committed by a person outside the European Union is not sufficient. Accordingly, the appellant claims that the General Court erred in law and disregarded the conclusions to be drawn from the judgment of 8 October 1986, Leussink v Commission, (34) by holding, on the sole basis of such a comment by the Commission, that the Commission was not best placed to provide evidence of the leak and that, consequently, the case before it differed from that which gave rise to the judgment of 8 July 2008, Franchet and Byk v Commission. (35) 71. In the second place, the appellant submits, in essence, that the General Court failed to take into account certain evidence tending to show that the leak originated within the EU institutions. 72. In the third place, the appellant claims that, as a result of a misinterpretation of the Commission’s letter of 30 January 2017 and of Decision 220/2015/ANA of the European Ombudsman of 14 December 2017, referred to in paragraph 66 of the judgment under appeal, the General Court held that there was no evidence that OLAF was the origin of the leak. The appellant adds, in that regard, that nothing in the file indicates that the national authorities, to which the OLAF report had been sent, were questioned about the origin of the leak in the context of the investigations conducted by OLAF and the Commission. Moreover, the General Court failed to verify whether those investigations had been conducted diligently and did not respond to an argument by the appellant which claimed that that was not the case. 73. The Commission disputes those arguments and maintains that the second ground of appeal is unfounded. (c) Assessment 74. I shall examine together the three parts of the second ground of appeal in so far as they seek to call into question the way in which the General Court applied the rules on the burden of proof and the taking of evidence in the context of an action for damages in order to exclude the liability of OLAF and the Commission for the alleged breach of the obligation of confidentiality. 75. I would point out, as the General Court did in paragraph 48 of the judgment under appeal, that, in accordance with the case-law of the Court of Justice on the rules relating to the burden of proof and the taking of evidence in relation to the European Union incurring non-contractual liability under the second paragraph of Article 340 TFEU, it is, in principle, the party seeking to establish that liability which must show by way of conclusive proof that the conditions necessary for it to incur such liability have been satisfied. (36) 76. However, the Courts of the European Union have qualified those rules by placing the consequences of uncertainty as to the exact causes of damage on the author of the event giving rise to that damage, in the interests of compensating the victim and ensuring fairness. (37) 77. That rule was established by the Court in the judgment of 8 October 1986, Leussink v Commission, (38) in the particular context of the occurrence of a road traffic accident suffered by a Commission official while travelling on mission in a Commission vehicle driven by a Commission driver. In so far as it was established that the accident could have been caused by poor maintenance, inadequate inspection of the vehicle or negligent use, (39) and in so far as the Commission adduced no evidence enabling it to be established to which of those causes the accident was imputable, although it was best placed to provide evidence in that respect, the Court of Justice held that such uncertainty therefore had to be construed against it, and concluded that the accident was due to negligence for which the Commission was liable. (40) As Advocate General Slynn stated in his Opinion in the case which gave rise to that judgment, the Commission had produced no evidence capable of demonstrating that it had fully complied with its obligations, such as proof that the vehicle had been inspected at a garage or the results of the roadworthiness test of the vehicle, and had not succeeded in rebutting the prima facie case of a breach of its duty of care. 78. The Courts of the European Union have used that imputability mechanism in the context of actions for damages brought on account of the disclosure of confidential information held by OLAF. In its judgment of 12 September 2007 in Nikolaou v Commission, (41) the Court of First Instance recognised that it may be difficult or even impossible for victims of improper disclosure to identify the person responsible and the source of the disclosure and thus to provide proof of the conditions necessary to establish the Commission’s liability. (42) In the case that gave rise to that judgment, it was established that the information that had been leaked came from a source within OLAF. That body therefore appeared to be best placed to adduce evidence as to the exact causes of the leak. Noting that the Commission had merely ruled out OLAF’s liability, without putting forward any specific argument or evidence to establish the existence within OLAF of a control system capable of preventing leaks or to demonstrate that the information concerning the investigation at issue had been processed in a manner that guaranteed its confidentiality, and that it had provided no explanation or even put forward any credible hypothesis as to the circumstances in which the leak could have occurred, (43) the Court of First Instance held that any uncertainty as to the circumstances in which the breach of the confidentiality rules had occurred had to be construed against the Commission. (44) 79. Similarly, in the judgment of 8 July 2008, Franchet and Byk v Commission, (45) the Court of First Instance presumed that the source of the leak of confidential information was to be attributed to OLAF, even though both OLAF and the French authorities were in possession of the illegally disclosed information. As a first step, the Court of First Instance carried out a detailed examination of the various types of factual evidence in the file and of the context in which the damage occurred, before taking into account, subsequently, the fact that the Commission did not rely on the liability of authorities external to the European Union, namely the French authorities. (46) 80. The Civil Service Tribunal held to the same effect in its judgment of 11 May 2010, Nanopoulos v Commission. (47) 81. In the light of that case-law, the presumption that the infringement of certain rules, including the obligation of confidentiality, may be attributed to a specific perpetrator, and the limitation of the burden of proof which that entails, presuppose that two conditions be satisfied. First, an applicant must, on the basis of a body of evidence, show that it is likely that the harmful event is attributable to an identified perpetrator. Second, where a certain degree of likelihood has been established, the defendant institution must prove by specific arguments or evidence and by credible explanations or hypotheses that the damage is not attributable to it. Thus, in a situation in which the evidence provided by an applicant enables the Courts of the European Union to infer the existence of a probable or plausible causal link, that rule lightens the burden of proof borne by the applicant and requires the defendant institution that appears, in view of the nature of the damage, to be best placed to adduce evidence, to prove that it did not infringe its obligations. 82. However, that also implies that the General Court must exercise its powers to the full. The specific purpose of an action for non-contractual liability is linked to the protection of the rights of an individual. (48) Where an individual cannot obtain the annulment of an act or conduct which has caused damage to him or her by means of one of the legal remedies for the review of legality, he or she must always be entitled to claim compensation where his or her rights have been infringed. (49) The relationship between legal remedies is aimed precisely at preventing such a person from being inadequately or wrongfully compensated. (50) In the judgment in Hamoudi v Frontex, (51) the Court of Justice clearly recalled the requirements incumbent on the General Court in actions for non-contractual liability in order to ensure the necessary effective judicial protection of individuals. Thus, the General Court must: – take into account the particular circumstances of the case before it in order to determine whether the rules on the burden of proof and the taking of evidence impose on an applicant a burden of proof which is excessively difficult, if not impossible, in which case those rules must be adapted; – conduct a close examination of the facts; and – adopt the necessary measures of inquiry. 83. As the Court of Justice noted in paragraph 81 of that judgment, ‘the General Court may not simply dismiss claims made by applicants on the ground of insufficient evidence, when it is that court that has the power … to remove any uncertainty there might be as to the correctness of those claims, or to explain the reasons for which such a document could not, in any event and whatever its content, be material to the outcome of the dispute’. (52) 84. In the present case, I consider that the General Court failed to comply with the rules laid down in the case-law concerning the burden of proof. 85. In the first place, the General Court was wrong, in my view, to hold, in paragraph 62 of the judgment under appeal, that the Commission was not best placed, within the meaning of the case-law relating to the qualification of the burden of proof, to adduce evidence establishing the cause of the leak. 86. First of all, the General Court failed to take into account the particular context of that action, whereas the Courts of the European Union have previously held, in similar cases, that it may be difficult or even impossible for victims of an improper disclosure to identify both the person responsible and the source of that disclosure, and thus to provide proof of the conditions necessary to establish liability. As the European Court of Human Rights has held, ‘the distribution of the burden of proof and the level of persuasion necessary for reaching a particular conclusion are intrinsically linked to the specificity of the facts, the nature of the allegation made and the [right enshrined in the European Convention for the Protection of Human Rights and Fundamental Freedoms] at stake’. (53) 87. Next, contrary to what the General Court maintains in paragraph 62 of the judgment under appeal, it seems to me undeniable that, in circumstances such as those at issue, OLAF and/or the Commission were, in relation to the appellant, best placed to determine whether the damage allegedly suffered was the result of their own action or omission or rather of that of the French and Belgian judicial authorities to which the OLAF report was lawfully communicated. In that regard, the conduct of the two internal investigations by OLAF and by the Commission, to which the General Court briefly refers in paragraph 66 of the judgment under appeal, shows that those two institutions had, a priori, resources that the appellant did not have available to it, given the subject matter and nature of the harmful event. 88. Lastly, the General Court’s reasoning seems to me to be contradictory. Although it stated in paragraph 62 of the judgment under appeal that the Commission was not best placed to provide evidence enabling the cause of the leak to be established, it nevertheless attached, in paragraph 65 of that judgment, a preponderant weight to the Commission’s claim that the origin of the leak could have been external to the EU’s institutions. 89. In the second place, in a situation such as that at issue, where there were several potential perpetrators, the General Court did not require the Commission to specify, by means of concrete evidence, the measures taken to ensure the confidentiality of the information contained in the OLAF report and of the information sent to the national authorities concerned. However, those measures are essential for several reasons. First of all, they concern information relating to acts that may be subject to criminal prosecution, since OLAF is not acting as an ‘ordinary whistle-blower’, but as an office vested with powers of investigation, as the Court of Justice pointed out in its judgment of 11 January 2024, Planistat Europe and Charlot v Commission. (54) Next, the disclosure of that information to the press is, per se, likely to result in certain material and non-material damage to the persons concerned. Lastly, those persons are not addressees of the investigation report of which they are the subject and cannot, in accordance with settled case-law, bring an action for annulment of that report in so far as it does not produce binding legal effects. (55) 90. In the third place, the General Court failed to investigate the evidence submitted to it by both IMG and the Commission. It did not assess either the relevance and probative value of the evidence on which the appellant based the liability of OLAF and the Commission, or the allegations made by the Commission in order to rebut that presumption of liability. 91. However, it was for that court, as the court of first instance, to establish or determine, in the most accurate and precise manner possible, whether the event giving rise to the damage was attributable to an internal EU actor, namely OLAF or the Commission, in which case the Courts of the European Union had jurisdiction, or to an actor external to it, namely the French or Belgian judicial authorities, in which case only the national court had jurisdiction. (56) To that end, it was for the General Court to determine whether the various factual indications relied on by the appellant to demonstrate that the leak was attributable to OLAF or the Commission and whether the context in which that information was disclosed to the press were sufficient to establish a sufficient degree of plausibility or certainty such that OLAF or the Commission were to be presumed liable. However, it must be noted that, in paragraph 54 of the judgment under appeal, the General Court merely referred to the letter sent to the President of the European Parliament, in which the Director-General of OLAF asked the President to take the necessary measures to put an end to the dissemination of the OLAF report. Although that evidence could suggest the existence of an internal leak within the institution, the General Court did not rule on its relevance or its probative value and did not draw any conclusions from it. 92. It follows that the General Court’s reasoning does not make it possible to ascertain the reasons why the Commission should not be held responsible for the leak and, consequently, why the European Union’s liability should be excluded rather than established. 93. It should be added that legal uncertainty in the sphere of non-contractual liability must be proven, unless that constitutes a denial of justice contravening Articles 41 and 47 of the Charter of Fundamental Rights of the European Union. (57) In general, I consider that, since the Commission is responsible for the confidentiality of OLAF reports, it cannot, in the event of a leak of confidential information which has caused damage, merely assert that, since the perpetrator of the leak has not been identified, it cannot be held liable. On the contrary, I consider that, since it is bound by the obligation of confidentiality, any breach of that obligation should be attributable to it, unless it adduces evidence to the contrary. It seems to me that, in the matter at issue, the Court should do more than merely alleviate the burden of proof, and should reverse it as regards the imputability of the breach. 94. I also agree that the European Union cannot be required to pay compensation for damage that it did not cause. The burden of reparation must be borne by the authority that disclosed or allowed the disclosure of the confidential information at issue. (58) Holding the Commission and OLAF responsible for damage that they may not have committed is a solution that appears to be unfair. However, to exclude, on a hypothetical basis, the liability of OLAF and the Commission where the entity responsible for the disclosure has not been identified seems to me to be equally unfair, in so far as such a solution risks resulting in a lack of effective judicial protection for the appellant, who may not be compensated or may receive insufficient compensation, even though the damage it has suffered appears to be actual and certain. 95. In the light of all those considerations, I take the view that the General Court erred in law, in paragraph 67 of the judgment under appeal, in concluding that there was uncertainty as to the origin of the leak, ‘in the absence of evidence to that effect’, and in concluding that it could not be attributed to the Commission and OLAF, in circumstances where it had not sufficiently investigated the evidence produced by both the appellant and the Commission for the purpose of identifying the perpetrator of the harmful event. 96. That error of law necessarily vitiated the General Court’s findings in paragraph 92 of the judgment under appeal relating to a possible obligation on the part of the Commission to act, on which the appellant relies in the present case in support of its fourth ground of appeal. 97. Consequently, I propose that the Court of Justice uphold the second ground of appeal as well founded. 3. The third ground of appeal, alleging incorrect assessment of the plea of illegality based on breach of the duty to have regard for the welfare of officials 98. By its third ground of appeal, the appellant disputes the reasoning set out in paragraphs 71 to 74 of the judgment under appeal, at the end of which the General Court rejected the plea of illegality in so far as it was based on a breach of the duty to have regard for the welfare of officials. (a) The judgment under appeal 99. The General Court recalled, in paragraph 71 of the judgment under appeal, the scope of the duty to have regard for the welfare of officials, as established by the Court of Justice in the judgment of 12 November 2020, Fleig v EEAS. (59) In paragraph 72 of the judgment under appeal, the General Court pointed out that that duty specifically concerns the obligations of the EU institutions towards their officials and other servants, and therefore drew the conclusion, in paragraph 73 of the judgment, that that duty was not applicable in the present case. (b) Arguments of the parties 100. The appellant submits, in essence, that the General Court erred in law by limiting the scope of the duty to have regard for the welfare of officials to the obligations of the institutions of the European Union towards their officials and other servants. To that end, the appellant refers to a number of judgments in which the Court of Justice has confirmed the existence of that duty in other areas of EU law, in which the institutions of the European Union have administrative and management powers, such as the management of the European Agricultural Guidance and Guarantee Fund (EAGGF), the export licence system, the common commercial policy and the protection against dumping. 101. The Commission argues that the fifth ground of appeal is ineffective. (c) Assessment 102. The fifth ground of appeal must, in my view, be rejected as inadmissible. 103. It follows from the second subparagraph of Article 256(1) TFEU, the first paragraph of Article 58 of the Statute of the Court of Justice of the European Union and Article 168(1)(d) of the Rules of Procedure of the Court of Justice that an appeal must indicate precisely the legal arguments specifically advanced in support of the appeal, failing which the appeal or the ground of appeal in question may be inadmissible. According to settled case-law, a ground of appeal must be declared inadmissible if the argument supporting it is not sufficiently clear and precise to enable the Court to exercise its powers of judicial review, in particular because the essential elements on which the line of argument is based are not indicated sufficiently coherently and intelligibly in the text of the appeal, which is worded in a vague and ambiguous manner in that regard. (60) 104. In the present case, although the appellant indicates the contested elements of the judgment under appeal, it must be acknowledged that its argument lacks precision, consistency and clarity. In paragraph 55 of its appeal, it merely copies footnote 42 to the Opinion of Advocate General Van Gerven in Nölle (61) and reproduces the case-law cited by him, whereas those references to case-law concern not the duty to have regard for the welfare of officials but the principle of sound administration, as the Commission rightly points out. Furthermore, although the appellant cites, in support of its third ground of appeal, point 28 of that Opinion, in which Advocate General Van Gerven referred[, in the French-language version,] to the ‘principe de sollicitude’ (‘duty of care’), it must be noted that the Court of Justice, in the [French-language version of the] judgment of 22 October 1991, Nölle, (62) chose to refer to the ‘devoir de diligence’ (duty to act diligently). 105. In so far as the appellant does not set out the reasons why such references are relevant in its situation, I propose that the Court of Justice reject the third ground of appeal as inadmissible. 4. The fourth ground of appeal, alleging incorrect assessment of the plea of illegality based on breach of the duty to act diligently 106. By its fourth ground of appeal, directed against paragraphs 78 to 101 of the judgment under appeal, the appellant claims that the General Court erred in law in holding, in essence, that the Commission was not required, by virtue of the duty incumbent on it to act diligently, publicly to condemn the leak of the OLAF report to the press and to put an end to the dissemination of false information resulting therefrom, by means of the publication of a press release. (a) The judgment under appeal 107. In paragraph 80 of the judgment under appeal, the General Court held that, in order to determine whether the Commission had committed a sufficiently serious breach of a rule of law intended to confer rights on individuals on account of an omission to act, it was necessary to determine, in the light of the case-law referred to in paragraphs 76 to 79 of that judgment, (i) the existence of a legal obligation to act, (ii) the existence of discretion on the part of the institution in question, and (iii) a manifest and serious breach by that institution of the limits placed on that discretion. 108. After recalling, in paragraphs 82 to 84 of the judgment under appeal, the scope of the duty to act diligently, the General Court examined, in paragraphs 86 to 93 of that judgment, whether that duty entailed a legal obligation to act such as that relied on by the appellant. After recalling, in paragraphs 87 to 90 of that judgment, the relevant provisions of Regulation No 883/2013, the General Court held that, despite the resulting obligation incumbent on the Commission to maintain the confidentiality of OLAF investigations, the duty to act diligently could not impose on it such an obligation to act in the absence of a breach of that obligation of confidentiality and since responsibility for the leak of the OLAF report could not be attributed to it. 109. In paragraph 94 of the judgment under appeal, the General Court therefore held that the appellant had not established that the Commission was under an obligation to act in the present case, thus concluding, in paragraph 95 of the judgment, that the alleged omission was not capable of triggering liability on the part of the European Union. 110. In paragraphs 96 to 101 of the judgment under appeal, the General Court, assuming that such a legal obligation to act existed, examined whether the Commission had ‘in any event’ manifestly and gravely infringed the limits placed on its discretion in that case. Holding that that had not been the case, it held, in paragraphs 102 and 103 of that judgment, that the fourth instance of illegality had not been established and that, therefore, the first condition for liability on the part of the European Union to be triggered was not satisfied. (b) Arguments of the parties 111. The fourth ground of appeal is divided into four parts. 112. By the first part of the fourth ground of appeal, the appellant submits that the General Court’s findings in paragraphs 93 and 94 of the judgment under appeal are incorrect in so far as, contrary to the premiss on which that court relies, the Commission bears responsibility for disclosing the OLAF report. 113. By the second part of that ground of appeal, IMG submits that the General Court failed to respond to its complaint that, once the report had been made public, the Commission was in breach of its obligation of confidentiality under Article 10(3) of Regulation No 883/2013, irrespective of whether it was responsible for that disclosure. The appellant complains that the General Court examined the extent to which the Commission was required to act in the light of its responsibility for the harmful event. However, in its view, the confidentiality of that information should be ensured with all the more force given that the conclusions in question were provisional conclusions, reached at the end of a procedure which was not fully adversarial, the publication of which could cause harm to the persons concerned. 114. By the third part of that ground of appeal, the appellant disputes the grounds of the judgment under appeal, set out in paragraphs 98 to 100 thereof, which led the General Court to conclude, in paragraph 101 of that judgment, that ‘even assuming that the Commission was under a legal obligation to act in the present case, it cannot be held that the breach of the duty to act diligently alleged by the [appellant] constitutes a sufficiently serious breach of a rule of law intended to confer rights on individuals’. 115. According to the appellant, contrary to what the General Court held in paragraph 98 of the judgment under appeal, the scope of the Commission’s obligation to ensure the confidentiality of the OLAF report did not require clarification in a provision in order to be able to lead to a manifest and serious breach of the limits of that institution’s discretion. The appellant submits that, if that were the case, it would in fact be impossible to rely on such a breach and for the European Union to be held liable, since the provisions of EU law do not necessarily define their scope and it is for the Courts of the European Union to define it. 116. In addition, the appellant argues that the General Court failed to have regard to the case-law arising from its judgments of 15 March 1995, Cobrecaf and Others v Commission, (63) and of 9 July 1999, New Europe Consulting and Brown v Commission, (64) from which it follows that the Commission is under a duty to exercise care, even where it is not responsible for the leak of a confidential document. In those judgments, the Courts of the European Union examined whether the Commission had exercised care in rectifying an error it had made, failing which it would have incurred liability. The appellant acknowledges that, in the present case, in so far as the confidentiality of the OLAF report had been infringed, the obligation to ensure respect therefor had become devoid of purpose, as the General Court noted in paragraph 100 of the judgment under appeal. However, in such a situation, the appellant claims that it is necessary not to aggravate the damage that might result from the breach of confidentiality of the OLAF report by publicly condemning its leak and by providing information on the follow-up action planned in response to it. 117. By the fourth part of the fourth ground of appeal, the appellant criticises the General Court for failing to rule on the liability, if necessary, jointly and severally, of the Commission and OLAF on the grounds that they failed to take the precautionary measures necessary to safeguard the confidentiality of the OLAF report or the corrective measures required vis-à-vis the press and public opinion and, consequently, the appellant’s partners and donors. 118. The Commission disputes those arguments and argues that the fourth ground of appeal is unfounded. 119. In its view, the fourth ground of appeal is confused and obscure. The first part of the ground of appeal in question alleges a breach of the obligation to state reasons, even though that is not mentioned in the title of that ground, and the third part of the same ground of appeal is directed against superfluous reasons. It emphasises that, although the Commission and OLAF did not adopt the conduct expected by the appellant, they nevertheless reacted to the leak of the OLAF report by conducting internal investigations and, in the case of OLAF, by writing to the President of the European Parliament asking him to take measures. Furthermore, the Commission recalls that it did not follow up on the recommendations made by OLAF in the report. (c) Assessment 120. I consider that there is no need to examine the first part of the fourth ground of appeal, by which IMG disputes the merits of the assessments made by the General Court in paragraphs 93 and 94 of the judgment under appeal, or the fourth part of that ground of appeal, by which it criticises the General Court for not ruling on the liability of the Commission and OLAF, if need be jointly and severally, since they are closely linked to the second ground of appeal which I propose that the Court of Justice uphold. 121. The analysis carried out by the General Court in paragraphs 92 to 94 of the judgment under appeal is based on a premiss – that the harmful event is not attributable to OLAF and the Commission – which seems to me to be incorrect for the reasons set out in the examination of the second ground of appeal, in points 74 to 97 of the present Opinion. 122. As regards the second part of the fourth ground of appeal, I consider that it is unfounded. 123. Contrary to what the appellant claims and as evidenced by the first sentence of paragraph 93 of the judgment under appeal, the General Court did indeed rule on the appellant’s argument concerning the scope of the obligation of confidentiality and that of the duty to act diligently. According to the appellant, the obligation of confidentiality in respect of investigations conducted by OLAF as laid down in Article 10(3) of Regulation No 883/2013 constitutes an obligation of result, requiring the Commission to act diligently by publicly condemning the unauthorised disclosures and putting an end to the dissemination of false information, irrespective of whether the Commission is the author of that harmful event. In paragraph 92 of the judgment under appeal, the General Court held that the duty to act diligently to which the Commission is subject cannot impose on it, since it has not failed to fulfil that obligation of confidentiality and since responsibility for the leak of the OLAF report to the press cannot be attributed to it, an obligation to act such as that relied on by the appellant. Next, in paragraph 93 of that judgment, the General Court stated that ‘the duty to act diligently does not have the scope which the [appellant] ascribes to it’, adding that it is the leak of the OLAF report to the press, and not the omissions of which the Commission is accused by the appellant, which constitutes a failure to fulfil the obligation of confidentiality. The General Court therefore responded in a reasoned manner to the argument raised by the appellant at first instance. 124. As regards the third part of the fourth ground of appeal, it is, in my view, ineffective. 125. It is directed against the General Court’s assessment in paragraphs 96 to 101 of the judgment under appeal. I note that the General Court used the expression ‘in any event’ at the beginning of paragraph 96 of that judgment, which indicates that those grounds were included in the judgment under appeal purely for the sake of completeness. According to settled case-law, arguments directed against grounds included in a decision of the General Court purely for the sake of completeness cannot lead to the decision being set aside and are therefore ineffective. (65) 126. Consequently, I consider that the fourth ground of appeal should be rejected as in part ineffective and in part unfounded. 5. The fifth ground of appeal, alleging errors of law affecting the General Court’s assessment concerning the removal of the opinion of the Commission’s Legal Service from the file 127. The appellant challenges the grounds set out in paragraphs 116 to 123 of the judgment under appeal, which led the General Court to grant the Commission’s request to remove the opinion of its Legal Service from the case file. (a) The judgment under appeal 128. In paragraphs 116 to 121 of the judgment under appeal, the General Court set out all the principles which must be weighed up in the context of the production, before the Courts of the European Union, of a legal opinion from an institution the disclosure of which has not been authorised by that institution, referring to the considerations set out by the Court of Justice in paragraphs 53 to 56 of the judgment of 16 February 2022, Hungary v Parliament and Council, (66) paragraph 131 of the judgment of 28 June 2012, Commission v Éditions Odile Jacob, (67) and paragraph 70 of the judgment of 31 January 2020, Slovenia v Croatia. (68) 129. It was in the light of those principles that the General Court examined, in paragraph 122 of the judgment under appeal, the context in which the opinion of the Commission’s Legal Service had been delivered and the extent to which its production before the Courts of the European Union was justified by an overriding public interest, before granting, in paragraph 123 of that judgment, the Commission’s request to remove the opinion from the file. (b) Arguments of the parties 130. The fifth ground of appeal is divided into four parts. 131. By the first part of that ground of appeal, the appellant disputes the relevance of the judgments of 16 February 2022, Hungary v Parliament and Council, (69) and of 28 June 2012, Commission v Éditions Odile Jacob, (70) to which the General Court refers respectively in paragraphs 116, 117 and 118 of the judgment under appeal. According to the appellant, the first of those judgments concerned an opinion of an entirely different nature, since the opinion of the Council’s Legal Service had been delivered in the context of a legislative procedure concerning a politically sensitive subject in a case of exceptional importance. In the present case, by contrast, the opinion of the Legal Service is, the appellant maintains, a decisive document, relating exclusively to the case at hand. Due to the leak to the press, that document was already in the public domain, so that the appellant cannot be criticised for having circumvented the rules on access to documents. In its view, having regard to its nature and the circumstances of its disclosure, that opinion does not undermine either confidentiality or an overriding public interest and its disclosure is not likely to affect the freedom of opinion of that service or its ability effectively to defend the Commission’s final position before the Courts of the European Union. 132. As regards the judgment of 28 June 2012 in Commission v Éditions Odile Jacob, (71) the appellant maintains that the opinion of the Commission’s Legal Service in that case concerned the decision-making process relating to merger control proceedings and the EU legislation relating thereto. 133. By the second part of the fifth ground of appeal, the appellant argues that, in paragraph 119 of the judgment under appeal, the General Court relied on case-law that is not relevant and disregarded the appellant’s right to comment on a document which it did not itself disclose. 134. By the third part of that ground of appeal, the appellant argues that the General Court was not justified in claiming that only exceptionally can the principle of openness justify the disclosure, in judicial proceedings, of a document of an institution that has not been released to the public and which contains a legal opinion, since, in paragraphs 120 and 121 of the judgment under appeal, the General Court disregards the context of the case to which it refers and cites the case-law in an incomplete and inaccurate manner. 135. By the fourth part of the ground of appeal in question, the appellant criticises the General Court for having infringed the principle of equality of arms in a fair trial, the scope of which it recalls, by preventing it from relying on a decisive document which was in the public domain, even though all the other parties were aware of its content. (72) Furthermore, the General Court allegedly infringed the principle of adversarial proceedings, the scope of which the appellant also recalls, (73) by not allowing it to discuss all the evidence known to all on the pretext that the disclosure of that opinion had escaped the Commission’s vigilance. The appellant recalls that there is a breach of the right to a fair trial guaranteed by Article 6(1) of the European Convention on Human Rights and Fundamental Freedoms (74) where a State or administrative authority, in the present case the Commission, has prevented the appellant from using documents in its possession that would have helped it to plead its case, without any legitimate reason. (75) 136. The Commission submits that the fifth ground of appeal must be rejected as unfounded in so far as the grounds set out in paragraphs 122 and 123 of the judgment under appeal are not vitiated by any error of law. 137. It replies, first, that it is clear from the order of 14 May 2019, Hungary v Parliament, (76) that, as long as the institution concerned has not authorised access to an opinion of its legal service, the fact that it has leaked into the public domain has no bearing on whether such an opinion may be included in the file of a case before the Courts of the European Union. Furthermore, the Commission recalls that the General Court had dismissed the first three pleas of illegality relied on by the appellant in support of its action, with the result that, according to the Commission, the legal opinion could not be classified as ‘decisive’. 138. According to the Commission, the appellant appears to take the view that it is apparent from the judgment of 3 June 2021, Hungary v Parliament, (77) that the transparency of the legal opinions of EU institutions constitutes the rule, whereas it is exactly the opposite that follows, in particular, from paragraph 56 of that judgment. (c) Assessment 139. I consider that the analysis on the basis of which the General Court granted the Commission’s request to remove the opinion of its Legal Service from the case file is not vitiated by any error of law. 140. First, none of the arguments put forward by the appellant calls into question the relevance of the general principles identified by the Court of Justice in the judgments of 28 June 2012, Commission v Éditions Odile Jacob, (78) of 31 January 2020, Slovenia v Croatia, (79) and of 16 February 2022, Hungary v Parliament and Council, (80) which the General Court faithfully reproduced in paragraphs 116 to 121 of the judgment under appeal. The fact that the opinion of the Commission’s Legal Service has been disclosed and is in the public domain is clearly not a relevant factor for the purpose of assessing the extent to which it may be included in the file of a case before the Courts of the European Union. The only relevant question is whether the disclosure of that document was authorised by that institution. 141. Second, the arguments put forward by the appellant concerning the application of the principles of adversarial proceedings and equality of arms cannot succeed either. 142. I would point out that, in accordance with settled case-law, the principles of adversarial proceedings and equality of arms, in so far as they are corollaries of the concept of a ‘fair trial’, form an integral part of the principle of effective judicial protection of the rights that individuals derive from EU law, enshrined in Article 47 of the Charter of Fundamental Rights. (81) 143. The principle of adversarial proceedings generally confers on each party to proceedings the right to be apprised of the documents produced and observations made to the courts by the other party and to discuss them, and prevents the Courts of the European Union from basing their decision on facts and documents which the parties, or one of them, have not had an opportunity to examine and on which they have therefore been unable to comment. (82) 144. As regards the principle of equality of arms, it implies that each party must be afforded a reasonable opportunity to present its case, including evidence, under conditions that do not place it at a substantial disadvantage vis-à-vis its opponent. (83) 145. The aim of that principle is to ensure a procedural balance between the parties to judicial proceedings, guaranteeing the equality of rights and obligations of those parties as regards, inter alia, the rules that govern the taking of evidence and the adversarial hearing before the court and also those parties’ rights to bring an action. In order to satisfy the requirements associated with the right to a fair hearing, it is important for the parties to be apprised of, and to be able to debate and be heard on, the matters of fact and of law that will determine the outcome of the proceedings. (84) 146. The appellant may only rely on those principles in so far as the evidence produced before the Courts of the European Union has been obtained lawfully. (85) The Court of Justice held, in fact, in the judgment of 12 July 2022, Nord Stream 2 v Parliament and Council, (86) referred to by the General Court in paragraph 117 of the judgment under appeal, that, where evidence has been improperly produced by a party, such as internal documents covered by Regulation (EC) No 1049/2001, (87) the production of which has been neither authorised by the institution concerned nor ordered by an EU Court, it is necessary to weigh the interests of the respective parties to the proceedings in connection with their right to a fair hearing, taking into account the interests protected by the rules that have been breached or circumvented in obtaining that evidence. (88) Further, it held that the EU Court hearing a request for the withdrawal of such evidence must weigh in the balance, on the one hand, the interest of the applicant who produced those items of evidence, having regard, inter alia, to their usefulness for the purposes of assessing the merits of the action brought before it and, on the other hand, the interests of the opposing party which the retention in the file of those items of evidence could specifically and effectively harm. (89) 147. I note, however, that, in paragraphs 116 to 122 of the judgment under appeal, the General Court weighed up the interests involved in order to rule on the Commission’s request, noting, inter alia, that the production of the legal opinion at issue appeared to be guided by the appellant’s own interests in supporting its arguments, and that the appellant did not invoke any overriding public interest that could have justified a different conclusion. 148. Lastly, the case-law of the European Court of Human Rights, relied on by the appellant, cannot justify a different conclusion either, since it concerns the right of the parties to the dispute to examine and comment on the documents and evidence taken into consideration by the court, and not the question of whether, and, if so, under what conditions, a party to the dispute may produce before the court a legal opinion whose disclosure had not been authorised by its author or its addressee. 149. I propose, therefore, that the Court of Justice reject the fifth ground of appeal as unfounded. 150. In view of all those considerations and having regard to the validity of the second ground of appeal, alleging incorrect assessment of the condition relating to the imputability of the harmful event to OLAF or the Commission, I propose that the Court of Justice should set aside the judgment under appeal in so far as the General Court failed to comply with the rules on the burden of proof and the taking of evidence by disregarding the need to adjust the burden of proof in the light of the circumstances of the case and by failing to assess the relevance and probative value of the evidence provided by both the appellant and the Commission. 151. Since the General Court did not properly investigate the dispute in order to establish whether the conditions for non-contractual liability on the part of OLAF and the Commission were met, the state of the proceedings does not seem to me to permit final judgment to be given in the case. I therefore propose that the Court of Justice refer the case back to the General Court for it to rule on the appellant’s action and reserve the costs. V. Conclusion 152. In the light of all of the foregoing considerations, I propose that the Court of Justice should rule as follows: (1) Annul the judgment of the General Court of the European Union of 28 June 2023, IMG v Commission (T‑752/20, EU:T:2023:366); (2) Refer the case back to the General Court of the European Union; (3) Reserve the costs. 1 Original language: French. 2 T‑752/20, ‘the judgment under appeal’, EU:T:2023:366. 3 See paragraph 67 of the judgment under appeal. 4 External investigations are direct investigations of third parties involved in activities related to EU budget transactions (see Special Report No 1/2005 concerning the management of the European Anti-Fraud Office (OLAF), together with the Commission’s replies (OJ 2005 C 202, p. 1), paragraph 12). 5 T‑509/21, EU:T:2024:590. 6 See judgments of 28 October 1982, Groupement des Agences de voyages v Commission (135/81, EU:C:1982:371, paragraph 10), and of 18 January 2007, PKK and KNK v Council (C‑229/05 P, EU:C:2007:32, paragraph 114), and order of 24 November 2009, Landtag Schleswig-Holstein v Commission (C‑281/08 P, EU:C:2009:728, paragraph 22). 7 135/81, EU:C:1982:371. That case concerned a Luxembourg limited liability company in the process of formation whose capacity to be a party to legal proceedings was contested by the Commission. In paragraph 9 of its judgment, the Court of Justice held that ‘[the Commission] [could not] challenge the capacity to institute proceedings of a body which it [had] allowed to take part in a tendering procedure and whose tender it [had] rejected after a comparative examination of all those who submitted tenders’. 8 C‑229/05 P, EU:C:2007:32. 9 See, to that effect, judgment of the ECtHR of 19 November 2020, Efstratiou and Others v. Greece (CE:ECHR:2020:1119JUD005322114, § 43 and the case-law cited). 10 C‑183/17 P and C‑184/17 P, EU:C:2019:78. 11 See judgment of 5 September 2019, European Union v Guardian Europe and Guardian Europe v European Union (C‑447/17 P and C‑479/17 P, EU:C:2019:672, paragraph 99 and the case-law cited). 12 See also the order issued by the General Court on 2 July 2021 reserving the decision on the plea of inadmissibility for the final judgment. 13 C‑414/08 P, EU:C:2010:165, paragraph 52. 14 C‑666/20 P, EU:C:2022:225, paragraph 26. 15 See judgment of 24 March 2022, GVN v Commission (C‑666/20 P, EU:C:2022:225, paragraph 24 and the case-law cited). 16 See judgment of 24 March 2022, GVN v Commission (C‑666/20 P, EU:C:2022:225, paragraph 26 and the case-law cited). 17 See judgment of 18 December 2025, Hamoudi v Frontex (C‑136/24 P, ‘the judgment in Hamoudi v Frontex’, EU:C:2025:977, paragraph 68 and the case-law cited). 18 See the judgment in Hamoudi v Frontex (paragraph 69 and the case-law cited). See, also, the order delivered today in the case CW v Eurojust and Europol (C-565/25 P, paragraph 28 and the case-law cited). 19 Forster, N., La responsabilité sans faute de l’Union européenne, Doctoral thesis defended on 8 November 2019, Bruylant, Brussels, 2021, paragraphs 218 (p. 297) and 219 (p. 299). 20 Forster, N., op. cit., paragraph 219 (p. 299). 21 Forster, N., op. cit., paragraph 219 (p. 299). 22 C‑679/23 P, EU:C:2025:976. 23 See judgment of 18 December 2025, WS and Others v Frontex (Joint return operation) (C‑679/23 P, EU:C:2025:976, paragraph 149 and the case-law cited). 24 See judgment of 18 December 2025, WS and Others v Frontex (Joint return operation) (C‑679/23 P, EU:C:2025:976, paragraph 150 and the case-law cited). 25 See judgment of 18 December 2025, WS and Others v Frontex (Joint return operation) (C‑679/23 P, EU:C:2025:976, paragraph 150 and the case-law cited). See also the Opinion of Advocate General Wahl in European Union v Kendrion (C‑150/17 P, EU:C:2018:612, point 50) and, in the academic literature, Wildermeersch, J., Contentieux de la légalité des actes de l’Union européenne : le mythe du droit à un recours effectif, Bruylant, Brussels, 2019, in particular, paragraph 625 (p. 484). 26 Wildermeersch, J., op. cit., paragraph 625 (p. 484), and Forster, N., op. cit., paragraph 228 (pp. 306 and 307). 27 See Forster, N., op. cit., paragraph 223 (pp. 301 and 302). 28 T‑259/03, EU:T:2007:254. In that judgment, the General Court held that ‘in circumstances where [information relating to OLAF’s recommendation to initiate proceedings against the applicant] is communicated, directly or indirectly, to a journalist, the leak must be regarded not only as a cause sine qua non of the damage resulting from the publication of that information, but also as a sufficiently direct cause of that damage’ (paragraph 320). 29 T‑48/05, EU:T:2008:257, paragraph 183. 30 T‑838/16, EU:T:2019:494, paragraph 321. 31 Regulation of the European Parliament and of the Council of 11 September 2013 concerning investigations conducted by the European Anti-Fraud Office (OLAF) and repealing Regulation (EC) No 1073/1999 of the European Parliament and of the Council and Council Regulation (Euratom) No 1074/1999 (OJ 2013 L 248, p. 1). 32 T‑48/05, EU:T:2008:257. 33 I would point out that the conclusion reached by the General Court is not isolated in the case-law, since the full court of the Civil Service Tribunal reached an identical conclusion in a case extremely close to the present case, which gave rise to the judgment of 13 January 2010, A and G v Commission (F‑124/05 and F‑96/06, EU:F:2010:2). In that case, ‘the Commission … and OLAF were not the only bodies in possession of the minutes of [the] interview with the applicant, since they had been passed to the Belgian national authorities with a view to possible prosecution’ (paragraph 215). Holding that it could not be considered that ‘the Commission was best placed to provide evidence enabling the cause of the leak to be established’, the EU judicature reached the same conclusion as the General Court in the judgment under appeal, namely that ‘the uncertainty as to the source of that leak cannot be construed against [the Commission]’ (paragraph 214). 34 169/83 and 136/84, EU:C:1986:371. 35 T‑48/05, EU:T:2008:257. 36 See the judgment in Hamoudi v Frontex (paragraph 71). 37 Quézel-Ambrunaz, C., Essai sur la causalité en droit de la responsabilité civile, Dalloz, Paris, 2010, in particular p. 255. 38 169/83 and 136/84, EU:C:1986:371. 39 See judgment of 8 October 1986, Leussink v Commission (169/83 and 136/84, EU:C:1986:371, paragraphs 15 and 16). See also the Opinion of Advocate General Slynn in Leussink v Commission (169/83 and 136/84, EU:C:1986:265). 40 See judgment of 8 October 1986, Leussink v Commission (169/83 and 136/84, EU:C:1986:371, paragraph 17). 41 T‑259/03, EU:T:2007:254. 42 See judgment of 12 September 2007, Nikolaou v Commission (T‑259/03, EU:T:2007:254, paragraph 196). 43 See judgment of 12 September 2007, Nikolaou v Commission (T‑259/03, EU:T:2007:254, paragraphs 196 and 198). In that judgment, the Court of First Instance held that ‘it was for the Commission to explain, on behalf of [OLAF], how that leak could have occurred in order to demonstrate, if necessary, that the abovementioned obligation incumbent on the Director of OLAF had not been infringed. If the Commission does not provide such explanations, it must be presumed that the leak resulted from a breach of Article 8(3) of Regulation (EC) No 1073/1999 [of the European Parliament and of the Council of 25 May 1999 concerning investigations conducted by the European Anti-Fraud Office (OLAF) (OJ 1999 L 136, p. 1)], committed by the Director of OLAF in the performance of his duties, within the meaning of Article 288 EC [(now Article 340 TFEU)]’ (paragraph 197). 44 See judgment of 12 September 2007, Nikolaou v Commission (T‑259/03, EU:T:2007:254, paragraph 196). 45 T‑48/05, EU:T:2008:257. In the case which gave rise to that judgment, the damage resulted from the disclosure to the press of confidential information held by OLAF, the Commission and the French judicial authorities. 46 See judgment of 8 July 2008, Franchet and Byk v Commission (T‑48/05, EU:T:2008:257, paragraph 203). 47 F‑30/08, EU:F:2010:43, paragraph 169. 48 See, in that regard, paragraph 103 of the judgment in Hamoudi v Frontex, in which the Court of Justice held that an action for non-contractual liability under Article 268 TFEU may be the only legal remedy capable of ensuring, to the requisite standard, judicial protection before the EU judicature against a Union agency or institution. 49 See Forster, N., op. cit., paragraph 290 (p. 386). 50 See judgment of 18 September 2014, Holcim (Romania) v Commission (T‑317/12, EU:T:2014:782, paragraph 79 and the case-law cited). 51 See the judgment in Hamoudi v Frontex (paragraphs 72 to 80). 52 See the judgment in Hamoudi v Frontex (paragraph 81 and the case-law cited). 53 See, to that effect, the Opinion of Advocate General Norkus in Hamoudi v Frontex (C‑136/24 P, EU:C:2025:257, point 18), and the case-law of the ECtHR cited in footnote 30 to that Opinion: judgments of 13 February 2020, N.D. and N.T. v. Spain (CE:ECHR:2020:0213JUD000867515, § 85), and of 18 November 2021, M.H. and Others v. Croatia (CE:ECHR:2021:1118JUD001567018, § 268). 54 C‑363/22 P, EU:C:2024:20, paragraph 75. 55 See judgment of 30 November 2023, Sistem ecologica v Commission (C‑787/22 P, EU:C:2023:940, paragraphs 66 and 154). 56 Although OLAF and the national authorities concerned contribute, through their exchanges of information, to the achievement of the same objective, namely the fight against fraud and damage to the financial interests of the European Union, there are no general or specific provisions, in the context of the enhanced administrative cooperation between those actors, governing the conditions under which OLAF or the national authorities concerned may be held non-contractually liable for a breach of the obligation of confidentiality of investigation reports drawn up by OLAF, with the result that those conditions fall, as regards liability, under two different legal systems. In the absence of a mechanism for joint and several liability (Europol), or joint liability (Frontex) and in the absence of the implementation of in solidum liability, OLAF is liable for any damage it causes to a person as a result of the unauthorised disclosure of its investigation report and each Member State is liable, in accordance with its national law, for any damage caused to an individual as a result of the processing, including the unauthorised disclosure, of the investigation report it has obtained from OLAF. 57 Forster, N., points out that uncertainty is a blind spot that is detrimental to the judicial protection of individuals (op. cit., paragraph 256, (p. 338)). In the preface to Joisten, C., L’incertitude causale en droit de la responsabilité civile, Larcier, Brussels, 2024, Professor Bernard Dubuisson raises a question that I find particularly relevant: ‘How and why [is it] permitted to give legal certainty to something that is not necessarily certain in reality[?]’ (p. 9). 58 Forster, N., op. cit., paragraph 323. 59 C‑446/19 P, EU:C:2020:918. 60 See judgment of 11 December 2025, ABLV Bank v SRB (C‑602/22 P, EU:C:2025:953, paragraphs 45 and 46 and the case-law cited). 61 C‑16/90, EU:C:1991:233. 62 C‑16/90, EU:C:1991:402. 63 T‑514/93, EU:T:1995:49. 64 T‑231/97, EU:T:1999:146. 65 See judgment of 26 September 2024, WEPA Hygieneprodukte and Others v Commission (C‑795/21 P and C‑796/21 P, EU:C:2024:807, paragraph 82 and the case-law cited). 66 C‑156/21, EU:C:2022:97. 67 C‑404/10 P, EU:C:2012:393. 68 C‑457/18, EU:C:2020:65. 69 C‑156/21, EU:C:2022:97. 70 C‑404/10 P, EU:C:2012:393. 71 C‑404/10 P, EU:C:2012:393. 72 The appellant relies, in that context, on the judgments of the ECtHR of 27 October 1993, Dombo Beheer B.V. v. the Netherlands (CE:ECHR:1993:1027JUD001444888, § 33); of 7 June 2001, Kress v. France (CE:ECHR:2001:0607JUD003959498, § 72); and of 19 September 2017, Regner v. Czech Republic (CE:ECHR:2017:0919JUD003528911, § 146). 73 The appellant relies, in that context, on the judgment of the ECtHR of 28 August 1991, Brandstetter v. Austria (CE:ECHR:1991:0828JUD001117084, § 67). 74 Signed in Rome on 4 November 1950. 75 The appellant refers, in that regard, to the judgment of the ECtHR of 9 June 1998, McGinley and Egan v. the United Kingdom (CE:ECHR:1998:0609:JUD002182593, §§ 86 and 90). 76 C‑650/18, EU:C:2021:426, paragraph 17. 77 C‑650/18, EU:C:2021:426. 78 C‑404/10 P, EU:C:2012:393. 79 C‑457/18, EU:C:2020:65. 80 C‑156/21, EU:C:2022:97. 81 See order of 12 November 2025, Fashion TV RO and Maestro (C‑475/24, EU:C:2025:898, paragraph 45 and the case-law cited). 82 See judgment of 4 December 2019, H v Council (C‑413/18 P, EU:C:2019:1044, paragraph 103 and the case-law cited). 83 See the judgment in Hamoudi v Frontex (paragraph 77 and the case-law cited). 84 See order of 12 November 2025, Fashion TV RO and Maestro (C‑475/24, EU:C:2025:898, paragraph 46 and the case-law cited). 85 See judgment of 12 July 2022, Nord Stream 2 v Parliament and Council (C‑348/20 P, EU:C:2022:548, paragraph 129 and the case-law cited). 86 C‑348/20 P, EU:C:2022:548. 87 Regulation of the European Parliament and of the Council of 30 May 2001 regarding public access to European Parliament, Council and Commission documents (OJ 2001 L 145, p. 43). 88 See judgment of 12 July 2022, Nord Stream 2 v Parliament and Council (C‑348/20 P, EU:C:2022:548, paragraph 130). 89 See judgment of 12 July 2022, Nord Stream 2 v Parliament and Council (C‑348/20 P, EU:C:2022:548; paragraph 131).