Can a conversation between a lawyer and a client be recorded, transcribed and used in a criminal trial? The Sarkozy/Herzog case shows why the answer cannot be reduced to a simple yes or no. Professional secrecy and defence rights protect the core of the relationship of trust. French case law has nevertheless recognised a narrow exception where the conversation itself provides evidence of the lawyer's involvement in an offence and is unrelated to the exercise of defence rights.

The relevant convictions became final in France on 18 December 2024. The European proceedings have not ended: three applications were communicated by the European Court of Human Rights to the French Government on 29 June 2026. Communication is neither a decision on admissibility nor a finding of a violation.

1. What happened in the Sarkozy/Herzog case

During an investigation, the French authorities intercepted telephone conversations between Nicolas Sarkozy and his lawyer, Thierry Herzog. According to the French judgments, the conversations concerned an attempt to obtain confidential information about judicial proceedings through a judicial officer, in return for support in securing a post in Monaco.

Sarkozy, Herzog and Gilbert Azibert were convicted of offences relating to corruption and influence peddling. On 18 December 2024, the Criminal Division of the Cour de cassation dismissed the appeals on points of law in case 23-83.178, identified as ECLI:FR:CCASS:2024:CR01482. That dismissal made the relevant French convictions final.

The legal significance of the case is not confined to its political figures. It concerns the boundary between confidential legal advice and a conversation alleged to reveal the lawyer's own participation in a criminal offence.

2. The narrow test accepted by the Cour de cassation

The French judgment did not hold that every lawyer-client communication may be used as evidence. It accepted the use of particular intercepted conversations because two crucial requirements were met cumulatively:

  1. the content provided evidence capable of supporting the lawyer's personal involvement in an offence; and
  2. the particular conversations were unrelated to the exercise of defence rights.

The second requirement is especially important. A conversation concerning the organisation of the defence, legal assessment, strategy or advice on the client's rights lies within the protected core. A general suspicion that the lawyer may be involved in unlawful conduct is not enough to remove the protection from every communication automatically.

3. What lawyer-client privilege protects

Privilege allows a person to speak candidly, disclose even potentially incriminating facts and obtain independent legal advice. Without that security, a client might withhold crucial information and the lawyer would be unable to prepare an effective defence.

The protection is not a personal immunity designed to conceal a lawyer's participation in a new offence. At the same time, an exception must not become a general gateway to surveillance. Necessity, proportionality, the purpose of the interception and the precise nature of each conversation must therefore be examined separately.

The label "lawyer-client" is not conclusive by itself. A court examines the actual content, timing, context and connection with the defence, while avoiding disclosure of any more protected material than is strictly necessary.

4. The protective 2016 judgment

The same Cour de cassation had identified the opposite boundary on 22 March 2016 in case 15-83.205, ECLI:FR:CCASS:2016:CR00782. It quashed the transcription of a conversation with the President of the Paris Bar because its content contained no indication that the lawyer had personally participated in an offence.

Comparing the two judgments is more useful than relying on a slogan. Where there is specific evidence of an offence committed by the lawyer and the conversation does not concern the defence, French case law permits its use by way of exception. Where personal involvement is not apparent, the protection is not displaced merely because an authority wishes to use the conversation.

5. What the ECHR is examining and what it has not decided

Applications nos. 9143/25, 11047/25 and 2416/25 were communicated to France on 29 June 2026. The ECHR raised questions concerning private life and correspondence under Article 8 of the European Convention on Human Rights, as well as fair-trial safeguards. The Court will examine whether the interference had a sufficient legal basis and safeguards against arbitrariness, and whether use of the conversations was compatible with a fair procedure.

Until a judgment is delivered:

  • it is not known whether all aspects of the applications will be declared admissible;
  • there has been no finding of a violation of Article 8 or Article 6;
  • the French judgment has not been set aside; and
  • no European rule has been adopted that permits or prohibits every such use regardless of the circumstances.

Communication means that the Government has been invited to respond to the Court's questions. It is an important procedural step, not a predetermined outcome. The three applications remain pending before the ECHR.

6. Why the French test does not transfer automatically to Greece

Judgments of the French Cour de cassation are not a direct source of Greek law. In Greece, the Constitution, the European Convention on Human Rights, the Code of Criminal Procedure, the rules on lawyers' professional secrecy, communications-confidentiality legislation and Greek case law on the lawful acquisition and use of evidence must each be examined in their own right.

The case provides a comparative example, not a ready-made answer. A Greek court would need to examine in particular:

  • which authority ordered the interception and on what legal basis;
  • whether its purpose and duration were specific and proportionate;
  • whether prior indications existed or the interception amounted to an unfocused search;
  • whether the content concerned the defence function or different conduct;
  • whether special safeguards for selection, sealing, transcription and destruction of irrelevant material were observed; and
  • whether the defence had a genuine opportunity to test authenticity and context.

7. Does the same principle apply to email, messaging apps and the cloud?

The underlying principle is not limited to telephone calls. Emails, messages in encrypted applications, cloud files, attachments and videoconferences may contain protected legal communications. Technical storage in a company account or on a mobile phone does not automatically remove their confidential character.

Care is nevertheless required when using carbon copies, shared folders and third-party recipients. Unnecessary forwarding may widen the group of people with access and make a claim to confidentiality more difficult. This does not mean that every mistaken recipient permanently destroys the protection. It means that purpose, the reasonable expectation of confidentiality and the measures taken must be assessed in each case.

8. What to do when such material appears in a case file

  1. Do not reproduce the material: limit copies, forwarding and extracts until lawfulness has been assessed.
  2. Record its origin: identify who collected it, under which order, on what date and through what chain of custody.
  3. Separate the conversations: distinguish defence advice from content alleged to concern independent participation in an offence.
  4. Raise the objection promptly: the deadlines and method of challenge depend on the stage of the proceedings.
  5. Request protective handling: seek sealing, restricted access, independent review or removal of irrelevant confidential material where the law provides for it.
  6. Check completeness: an isolated extract may convey a different meaning without the preceding and following messages.
  7. Preserve technical evidence: original files, metadata, logs and hashes are needed to assess authenticity and integrity.

A timely procedural response is critical. A general complaint that "privilege was breached", without identifying the conversation, legal basis and resulting harm to the defence, may not be sufficient.

9. What the case does not establish

  • It does not establish that lawyer-client privilege is absolute in every circumstance.
  • It does not establish that an allegation of criminal conduct is enough to override privilege.
  • It does not authorise the authorities to record all lawyers' communications indiscriminately.
  • It does not mean that a Greek court will apply the French test unchanged.
  • It does not mean that the ECHR has already upheld or dismissed the applicants' claims.

10. Frequently asked questions

Is every conversation confidential merely because I call my lawyer?

No, not automatically. Protection is linked to the relationship and function of legal advice. A communication that merely invokes a lawyer's title in order to organise a new offence is not the same as the exercise of defence rights.

May the police listen first and decide later?

Lawful interception requires a prior legal basis, a defined purpose and safeguards. The later discovery of material of interest does not automatically cure an interference that was unlawful or disproportionate from the outset.

What should I do if a message has been cut or transcribed incorrectly?

Request the fullest available original, the metadata, chain-of-custody record and a technical examination. Authenticity, completeness and context are distinct questions from whether the content is covered by privilege.

When will the ECHR decide?

There is no reliable date. Written observations follow communication, and further procedural stages may be required. Until a judgment is published, the applications remain pending.

11. Official sources

Legal information: The official sources were reviewed on 30 August 2026. The proceedings before the ECHR remain pending and this account should be updated when a new official act is published. This article provides general comparative information and is not individual legal advice on Greek or French criminal procedure.