Article 694-50 of the French Code of Criminal Procedure
The costs of executing European mutual assistance requests shall be borne by the executing State, except, where they may be considered exceptionally high, to be shared with the issuing State in the event of agreement between the competent authorities or, failing that, to be borne by the issuing State. However, the issuing State shall always bear the costs occasioned by a European Investigation Order concerning: 1° The transfer of the…