unlawfully obtained evidence

12 May 2005

Christian Curtil

Is it possible to record a person’s telephone conversation without his consent and use it as evidence in a trial? Can someone rely on a document stolen from the offices of another party? Or information obtained as a result of entrapment?

These questions raise the issue of whether evidence obtained in an unlawful or improper manner is admissible at trial. This note deals with the test of admissibility, firstly in criminal proceedings, and then in all other areas of French law.

Criminal law

Article 427 of the code of criminal procedure states:

Except where the law otherwise provides, offences may be proved by any mode of evidence and the judge decides according to his innermost conviction.

The judge may only base his decision on evidence which was submitted in the course of the hearing and adversarially discussed before him.”

Thus, French law does not authorisea judge in criminal proceedings to reject a piece of evidence even though it is obtained in an unlawful manner. Indeed, the judge may not consider how it was obtained but may only assess the evidence on the question of whether it is convincing. The parties are merely obliged to serve the evidence on all the parties.

The rule applies to the evidence used by both the defence and the victims, whether corporate entities or private persons. A defendant is even released from his professional or medical duty of confidentiality when such disclosure is needed for the purpose of his own defence.

Hence, on 11 June 2002, the courde cassation overruled a Court of Appeal judgment which had refused to examine evidence obtained from a poll to prove discriminatory behaviour.

However, this rule does not apply when the law expressly provides otherwise. For instance, article 205 of the code of civil procedure, which bans the children of divorcing couples from giving evidence in proceedings connected with the divorce. Therefore, illegally recorded conversations of the children would be inadmissible in criminal proceedings for non payment of subsidies to a spouse.

With a few rare exceptions, evidence obtained in an improper, or even criminal manner, will be admissible in criminal proceedings.

Other areas of French law

In contrast with criminal proceedings, evidence obtained in an unlawful or improper manner is inadmissible in all other areas of French law.

As an example, on 7 October 2004, the civil section of the cour de cassation reaffirmed that:

a private telephone conversation which is recorded and kept without the person’s knowledge is an improper process which makes the evidence inadmissible.”

Therefore, in a commercial or civil case, a defendant may consider the possibility of challenging the evidence on grounds of how it was obtained.

But what criteria do the French courts apply in deciding whether evidence was obtained illegally or improperly?

The evidence is admissible if both parties are supposed to have the same document or were in a position to legally access it, provided it is exchanged between them or their lawyers before trial. The rationale for this approach is that the evidence was legitimately available to the parties, notwithstanding that they actually obtained it in an unlawful or improper manner.

There is, however, one notable exception in labour law. When evidence is used by an employee against his employer, it is always admissible providing it has been obtained in the course of the professional activity. Although, interestingly, evidence must be lawfully obtained when used by an employer against an employee.


Therefore, the admissibility of evidence obtained unlawfully or improperly is generally clear:

  • in criminal proceedings, such evidence is admissible provided it is discussed in an adversarial way in court
  • in all other areas of French law, such evidence is only admissible where it has been obtained in an adversarial manner