James Mason commenting on "The Man Between" in 1974: "This film became very big on television in the U.S. In the cinema one demands of a thriller that the narrative thread be ever taut. The American televiewer makes no such demands since continuity is destined to be shattered by commercial interruption. Thus it often happens that what has been hitherto regarded as a failure in the cinemas will be a hit on the Late Late Show and vice versa."
Sir Carol Reed always felt that the script for this film wasn't quite right, and was constantly trying to get it rewritten during filming. At one point, he approached Evelyn Waugh to do a rewrite, but Waugh refused, claiming he couldn't understand the story.
Some film fans consider this movie as nothing more than a "Third Man" copy.
The opera on stage when Ivo and Susanne are trying to escape is Richard Strauss' "Salome". It shows the final scene where Salome is waiting for the head of Jochannan (John the Baptist).
Ljuba Welitsch's debut.