Mister Zehn Prozent - Miezen und Moneten

Psychopath is a 1968 film directed by Guido Zurli. The film is about Sigpress, a thief who steals jewels which he then returns to the owners in order to collect money as a reward. He is being tracked by Scotland Yard when he learns that the gem called the Eye of Allah is being escorted from London to Paris. On attempting to steal the jewel, he finds it's a fake which leads to his own investigation.