Traitor's Gate

Traitor's Gate is a 1964 West German-British co-production of a black-and-white crime film directed by Freddie Francis and starring Albert Lieven, Gary Raymond, Catherine Schell and Klaus Kinski. It was made by Rialto Film using Hammer Films' Freddie Francis and screenwriter Jimmy Sangster updating the 1927 novel The Traitor's Gate by Edgar Wallace to the mid-1960s. The film features a group of criminals planning to steal the Crown Jewels of the United Kingdom from the Tower of London. It was shot at Twickenham Studios and on location around London. The film's sets were designed by the art director Tony Inglis.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.

Poster © the film's rights holders.