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 Vienna Higher Regional Court (OLG 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. Concurrently, the Federal Competition Authority (BWB) was conducting antitrust proceedings. The companies involved cooperated in the antitrust proceedings and submitted leniency statements.

Through administrative assistance, the public prosecutor’s office requested the transfer of the antitrust files. These documents—including the leniency statements and settlement agreements along with their annexes—were incorporated into the criminal investigation file. Two of the companies involved lodged an objection to this and later filed an appeal with the OLG Vienna. The Vienna Higher Regional Court 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

First, 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 transmit their files to the public prosecutor’s office upon request. This generally applies to leniency statements and settlement agreements as well.

However, this is subject to the condition that the rules on disclosure 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 clarified the scope of protection under Article 31(3) of Directive (EU) 2019/1 (also known as the ECN+ Directive) to the effect that only the actual leniency statements and settlement submissions are protected. However, pre-existing evidence, as well as all documents and evidence submitted to illustrate, substantiate, or prove the statements in the leniency statement, are not covered by this protection.

Differentiated access rights for parties to the proceedings

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

To safeguard the rights of the defense, defendants in criminal proceedings must not, as a general rule, be denied access to leniency statements and settlement submissions—even if they did not draft them themselves.

However, such access must not be granted to other parties, such as victims of antitrust violations or private parties seeking to assert civil claims for damages. This would undermine the practical effectiveness of Article 31(3) of Directive (EU) 2019/1.

Conclusion

The ECJ confirms that the internal transfer of antitrust files to criminal prosecution authorities is generally permissible. However, with regard to access to files, a distinction must be made between defendants and other parties to the proceedings. This clarifies key principles regarding the disclosure of leniency statements and settlement agreements.

It is to be assumed that files from antitrust proceedings will continue to be transmitted in full. The responsibility for ensuring the accessibility of leniency statements to third parties thus lies with the law enforcement authorities.