The points of friction between arbitration and criminal matters have multiplied in recent years to the point that it seems useful to clarify the relationships that arbitration actors (arbitrators, counsel and arbitral institutions) can have with criminal authorities in consideration of applicable legal and professional rules. This study shows that arbitration actors in France are not obliged to report criminal offences that they may come to know about in the course of their mission. Nor should these actors be bound by an obligation of cooperation provided that confidentiality of arbitration, whether domestic or international, be recognized as a matter of principle.