This was Bonar Colleano's final film before he was killed in a car accident on August 18, 1958 at the age of 34, three weeks before the film was released.
According to the book "When the Snow Melts", the autobiography of producer Albert R. 'Cubby' Broccoli, this picture was one of three from Warwick Films which were "released within a year". The three movies were: 'The Man Inside' (1958), 'Killers of Kilimanjaro' (1959), and 'Tank Force!' aka 'No Time To Die' (1958).
Hiding out in Spain, Sam Carter adopts the pseudonym of "Dr. Sanson Carrasco" - a name borrowed from a character in "Don Quixote".
This film produced by Albert Broccoli has several actors that would later appear in the James Bond series also produced by Broccoli. Donald Pleasence appeared in You Only Live Twice and Walter Gotell appeared in numerous Bond films starting with From Russia With Love.