Nigel Davenport was first cast in a key supporting role, but upgraded to the second lead when Richard Harris was fired.
According to Nigel Davenport the reason Richard Harris was fired because he refused a military style haircut for the role of a British army officer.
Final credited official film of director André De Toth.
Nigel Davenport was originally cast as "Colonel Masters", but the sudden dismissal of Richard Harris led to his being promoted to the larger role of "Cyril Leech". His original role was taken over by Nigel Green.
This movie is considered a "Dirty Dozen" influenced picture. Both movies' story-lines involve convicts going on a World War II deadly mission. This film even uses the word "Dirty" in its title like The Dirty Dozen. Interestingly, this movie's cinematographer Edward Scaife was also the D.O.P. on The Dirty Dozen.