On October 30, 2025, the European Court of Justice (ECJ) issued a landmark ruling in Case C-2/23 regarding the protection of leniency statements under EU law. The preliminary ruling proceedings concerned the question of whether documents from antitrust proceedings may be transmitted to the public prosecutor’s office and which parties to the proceedings should be granted access to these documents.

Background of the Main Proceedings

The referral by the Higher Regional Court, Vienna (Oberlandesgericht Wien) was prompted by a preliminary investigation conducted by the Central Public Prosecutor’s Office for the Prosecution of Economic Crimes and Corruption (WKStA) against construction companies on suspicion of illegal collusion in public procurement procedures. At the same time, the Federal Competition Authority (BWB) was conducting antitrust proceedings. The companies involved cooperated in the antitrust proceedings and submitted leniency statements.

The public prosecutor's office has formally requested the transfer of the antitrust files through administrative assistance. These documents, including the leniency statements and settlement submissions together with their annexes, were incorporated into the criminal investigation file. Two of the companies involved lodged an objection to the inclusion of these documents in the criminal investigation file and later filed an appeal with the Higher Regional Court, Vienna. The Higher Regional Court, Vienna, then referred the matter to the ECJ with questions regarding the scope of EU law protection for the documents in question.

In its judgment, the ECJ established three key principles:

Admissibility of the transfer of files

Firstly, the ECJ clarified that national administrative assistance mechanisms are not subject to EU law. Article 101 TFEU does not preclude national regulations that require competition authorities and antitrust courts to transfer their files to the public prosecutor’s office upon request. This also applies to leniency statements and settlement submissions as well.

However, this is subject to the condition that the rules  governing the transmission of documents do not undermine the practical effectiveness of EU competition law. In particular, the attractiveness of leniency programs must not be undermined by the fact that companies willing to cooperate must fear disproportionate disadvantages resulting from the disclosure of voluntarily provided information.

Restrictive Scope of Protection

The ECJ provided clarification on the scope of protection under Article 31(3) of Directive (EU) 2019/1 (also known as the ECN+ Directive) determining that only the actual leniency statements and settlement submissions are protected. However, pre-existing information, as well as all documents and evidence submitted to set out, substantiate, or prove the statements made in the leniency statement are not covered by this protection.

Differentiated access rights for parties to the proceedings

The ECJ ’s distinction regarding access rights in the context of access to case files is particularly relevant in practice.

It is vital to ensure that the rights of the defence are protected. As a general rule, defendants in criminal proceedings must not be denied access to leniency statements and settlement submissions, even if they were not authors of those documents.

However, such access must not be granted to other parties, such as persons harmed by the cartel or private parties seeking to assert civil damages claims. Granting such access would compromise the practical effectiveness of Article 31(3) of Directive (EU) 2019/1.

Conclusion

The ECJ has confirmed that the internal transfer of antitrust files to criminal prosecution authorities is generally permissible. However, when it comes to access to files, it is important to distinguish between defendants and other parties involved in the proceedings. This clarifies key principles regarding the disclosure of leniency statements and settlement submissions.

It is to be assumed that files from antitrust proceedings will continue to be transmitted in full. It is therefore the responsibility of law enforcement authorities to ensure that leniency statements are accessible to third parties.