This Man Is Dangerous (1953)

On the run from international police, Special Agent Lemmy Caution arrives in the South of France and soon becomes embroiled in a scheme with the infamous gangster Siegella. Whilst seeming to co-operate with the underworld boss, Lemmy is secretly acting for the FBI, and intends using Miranda Van Zelden, a wealthy heiress, as bait to trap a gang of crooks and put an end to Siegella's exploits...