OD FLASH | The employer’s right to evidence: the admissibility of anonymized testimonies

Cass. Soc., March 19, 2025, no. 23-19.154

Anonymous testimonials, even if not corroborated by other evidence, may enable the employer to demonstrate the reality of the employee’s serious misconduct.

Since the reversal of case law by the French Supreme Court’s Plenary Formation on December 22, 2023 (no. 20-20.648 and no. 21-11.330), the rules governing the right to evidence continue to be clarified in the context of contentious relations between employers and employees.

This reversal establishes the admissibility in court of unfair evidence (the clandestine recording of the employee in the first case, and the collection of comments on the employee’s Facebook account inadvertently left open in the second), subject to its being indispensable to the exercise of the employer’s right to evidence.

In the March 19, 2025 decision referred to above, in order to prove the serious misconduct that led to the employee’s dismissal – i.e. aggressive and violent behavior, both verbal and physical – the employer produced two anonymous witness statements before the lower courts, witnessed by a court commissioner.

The Court of Appeal had decided that the said testimonies were not conclusive, given that they did not include the identity of the witnesses, the period during which they had worked with the employee, or their position within the company. Despite the employer’s offer to produce the identity of the witnesses solely for the members of the Court of Appeal, the latter concluded that the existence of serious misconduct had not been proven.

The French Supreme Court, hearing this case, censured the reasoning of the Court of Appeal: the production of the anonymized testimonies was essential to the exercise of the employer’s right to evidence, as it was obliged to ensure the safety and protect the health of its employees.

This decision runs counter to the usual position of the French Supreme Court, which refused to authorize the judge to base his decision “solely or decisively” on anonymous testimony (Cass. Soc., July 4, 2018, no. 17-18.241), on the grounds that it would infringe the rights of the defense. 

It should be noted that in this case the testimonies:

• Had been collected by a sworn commissioner of justice,
• Were made available to the judge in their non-anonymized version.

The admissibility of anonymous testimony is now possible, but not systematic: in a decision dated March 12, 2025, the French Labour Court ruled that anonymous testimony gathered as part of an internal investigation had no probative value (Cass. Soc., March 12, 2025, no. 23-18.11). As always in matters of fundamental rights and freedoms, the infringement must therefore be justified and proportionate.