Penultimate film directed by Seth Holt. This movie was actually Holt's final completed picture as his last film Blood from the Mummy's Tomb (1971) was not completed when Holt passed away.
Lead actor Richard Johnson has said that Seth Holt was one of the best directors he has ever worked with.
This movie was made and released only about a year after its source novel 'The Eliminator' by Andrew York was first published in 1966. 'The Eliminator' was also this film's working title.
Richard Johnson leads the cast in this 1960s spy film. Johnson was director Terence Young's first choice to play James Bond when casting Dr. No (1962). Johnson also appeared in the 60s spy flicks Deadlier Than the Male (1967) and its sequel Some Girls Do (1969).