Little Red Monkey

Little Red Monkey, released in the United States as Case of the Red Monkey, is a 1955 British spy film directed by Ken Hughes and starring Richard Conte, Rona Anderson and Russell Napier. Detectives from Scotland Yard investigate a series of murders of leading Nuclear scientist, and are intrigued by strange reports received about the crimes. The film was based on a popular BBC TV series of the same name, written by Eric Maschwitz and produced by Bill LyonShaw, which ran for six 30minute episodes in 1953.

Source: Wikipedia