"I have a recording, but I think it is unlawful, so it cannot be used." This is a very widespread belief among employees — and it is no longer entirely accurate. Following an important reversal of case law by the Cour de cassation (the French Supreme Court), evidence obtained by unfair means, such as a recording made without the employer's knowledge, may, in certain cases, be admitted before the judge. As a lawyer at the Mulhouse Bar, I defend employees across the Haut-Rhin: here, plainly, is what the law really says — and the precautions to take.
The principle changed in 2023
For a long time, evidence obtained by unfair means was systematically excluded from civil proceedings. In two judgments of 22 December 2023, the full bench (assemblée plénière) of the Cour de cassation reversed that position: such evidence — for example a recording made without the person's knowledge — is no longer automatically inadmissible before the civil judge, including the conseil de prud'hommes (the French labour court). This development is grounded in the right to evidence and the right to a fair trial (article 9 of the French Code of Civil Procedure; article 6 § 1 of the European Convention on Human Rights).
But two strict conditions
This reversal does not make everything admissible. When asked to exclude the evidence, the judge weighs the right to evidence against the other rights at stake, and admits the recording only on a twofold condition:
Unfairly obtained evidence is admitted only if:
- it is indispensable to the exercise of the right to evidence;
- the interference with the other party's rights is strictly proportionate to the aim pursued.
In other words, the judge assesses whether the use of this evidence undermines the fairness of the proceedings as a whole.
It is not a blank cheque
This is the most important point, and the most misunderstood. The requirement that the evidence be indispensable is a genuine condition: if you can prove the same fact by other means — through e-mails, witness statements, sworn declarations, documents — the covert recording may be excluded as not indispensable. Admissibility remains conditional and is assessed case by case. Recording out of reflex, without a strategy, is therefore rarely a good idea.
Warning: a criminal risk for you
Recording, without their consent, words spoken by a person on a private or confidential basis may constitute a criminal offence, punishable by one year's imprisonment and a fine of 45,000 euros (article 226-1 of the French Criminal Code). Two levels must be kept separate: a recording may be held admissible in civil proceedings while nonetheless being, in other respects, criminally punishable. Caution is all the more necessary because you may also capture the words of third parties who have nothing to do with your dispute.
What about text messages, e-mails or company documents?
The question often arises for an internal message or document. The rule is similar: you may produce documents that you became aware of in the course of your duties, provided that this production is strictly necessary for the exercise of your rights of defence in the dispute with your employer, and proportionate. Here again, everything is a matter of measure.
How I assist you
Evidence that is poorly chosen or poorly produced can weaken your case, and may even backfire against you. Before taking any step, I help you determine what is genuinely useful and admissible, to gather safer evidence where possible, and to build the strongest strategy before the conseil de prud'hommes (labour court) in Mulhouse. You are supported at every stage, in strict compliance with professional secrecy.
A dispute with your employer in Mulhouse or in the Haut-Rhin?
Frequently asked questions
Can I record my employer without their knowledge and use it before the labour court?
Since a 2023 reversal of case law, such a recording is no longer automatically excluded from the proceedings. But it is admissible only if it is indispensable to prove your rights and if the interference with the employer's rights remains strictly proportionate. It is therefore not a general right.
Is recording someone without their knowledge lawful?
Recording words spoken in private without the person's consent may constitute a criminal offence, punishable by one year's imprisonment and a fine of 45,000 euros (article 226-1 of the French Criminal Code). The admissibility of the evidence in civil proceedings and its criminal punishment are two separate questions.
Will my recording necessarily be accepted by the judge?
No. The judge assesses each case individually. If you have other means of proving the same fact, the recording may be excluded because it was not indispensable.
Can I produce text messages or e-mails from my employer?
You may produce documents that you became aware of in the course of your duties, provided that doing so is strictly necessary for your defence and proportionate. Here again, it is better to have what is usable checked before producing it.
What should I do before using such evidence?
Have it analysed before producing it: if wrongly used, it may backfire against you. A lawyer assesses its admissibility and builds the safest strategy with you.
This article provides general information on the state of the law and does not constitute legal advice. Every situation is unique: to have yours examined, contact the firm.