1980 film by Philippe Clair

Clovis Blaireau is a private detective. It is charged by Nadège de Courtaboeuf wife knew wealthy industrialist Prosper de Courtaboeuf, to obtain evidence of the infidelity of her husband. Clovis managed to penetrate the intimacy of Prosper, and became his friend. Following diverse Clovis and Prosper adventures will find themselves in Tunisis pursued by a band of Mafioso and by members of the Front of breaking load of Couscous.

Three little criminals get a tip for a great coup with lots of money in it. Unfortunately they lack the starting funds to buy the required welding torch. So they persuade their successful colleague Alphonse to join their team. But the well thought-out coup fails, and Alphonse is the only one of them who ends up in jail for several years. When he's released, he's out for revenge.