The Man Inside (1958)

An English bookkeeper (Nigel Patrick) who works for a jeweler steals a priceless jewel, and kills a man in the process. He flees to the continent, where he embarks on the life of his dreams; spending lavishly and pursuing women (including Anita Ekberg). A detective (Jack Palance) tracking him soon discovers he's not the only one searching for him, and begins to suspect there's more to the case than just an ordinary jewel theft.