Article 422 of the French Code of Criminal Procedure

A person who has joined as a civil party may no longer be heard as a witness.

However, the civil party is treated in the same way as a witness as regards the payment of compensation, unless the court decides otherwise.

Original in French 🇫🇷

Article 422

La personne qui s’est constituée partie civile ne peut plus être entendue comme témoin.

Toutefois, la partie civile est assimilée au témoin en ce qui concerne le paiement des indemnités, sauf décision contraire du tribunal.