The Cop, the Criminal and the Clown (2004)

Original title: C'est pas moi, c'est l'autre

A bungling robber steals and resells for next to nothing a seemingly worthless piece of art that had 50 00$ belonging to a member of the Marseillaise Mafia hidden its framework. Dressed as a priest in an effort to hide from the dangerous threats, he is then mistaken by two police officers for Claude Laurin, a police investigator who they think is undercover.