The Man Inside is a 1958 British crime adventure film directed by John Gilling and starring Jack Palance, Anita Ekberg, Nigel Patrick, Anthony Newley and Bonar Colleano. It was produced by Irving Allen and Albert R. Broccoli for Warwick Film Productions. The screenplay by David Shaw was based on the 1954 novel of the same name by M. E. Chaber. It was Bonar Colleano's final film role.

Plot

Sam Carter is a jeweller's clerk who dreams of stealing a fortune in diamonds and eventually does so, but he kills a man in the process. He then embarks on the high life, but is pursued across Europe by private detective Milo March, a woman named Trudi Hall, and two thugs, Martin Lomer and Gerard Heinz. These characters end up trying to outwit each other over the largest diamond, which is worth $700,000, on a train travelling to London. March describes the diamond as "$700,000 of unhappiness" because people are willing to do anything to get it.