The employee, the abusive boss, and the hard drive: a story of illegally obtained but admissible evidence
May 13th, 2026
It was bound to happen: the employer caught out not by an unfortunate text message or a surveillance camera, but by his own computer, searched by an employee during a suspension from work. And on April 1, 2026*— no April Fool’s joke — the Social Chamber held that these documents, obtained through unlawful access to the company’s IT system, would nevertheless be… admissible.
The framework has now been set by the Full Court decision of December 22, 2023: unlawfully or unfairly obtained evidence is not automatically excluded. The judge must balance the right to evidence against the other rights at stake. Two conditions govern admissibility: the evidence must be indispensable to the exercise of that right, and the infringement caused must be strictly proportionate to the aim pursued.
In this case, the employee had testified against his manager regarding the moral harassment of a colleague. The manager was criminally convicted. Shortly thereafter, the employee was suspended and then dismissed for gross misconduct, officially for disloyal conduct and improper use of his work computer. Unofficially, he argued, because he had dared to speak out.
To demonstrate the retaliatory nature of the dismissal, he produced three files extracted from the manager’s computer during his suspension: draft settlement agreements, a draft letter to the prosecutor, and documents revealing pressure intended to make him retract his testimony. The Court openly acknowledged that the evidence had been obtained unlawfully and infringed upon the manager’s privacy. However, it also found that these documents were “strictly necessary” for the employee’s defense and that he could not have achieved the same result through less intrusive means.
The infringement was deemed proportionate: three targeted files, not a generalized raid. On the other side of the scale, the stakes were considerable: establishing that an employee had been dismissed in retaliation for testimony concerning workplace harassment — a situation in which the Labour Code treats the nullity of the dismissal as a safeguard against retaliatory measures.
Our view: the message is clear. In matters involving harassment, retaliation against witnesses, and more broadly structural imbalances in access to evidence, the Court is willing to crack the traditional doctrine of evidentiary fairness. Employers have been warned: what takes place on their computers may, under certain conditions, find its way into the courtroom. And privacy alone will no longer suffice to erase what the digital record has preserved.
*Cass. Soc., 1er avril 2026, n°24-19.193
=> For any advice on employment law or social security law, please contact Guillaume Roland, partner: g.roland@herald-avocats.com