Sole writing credit of Lotte Colin, mother-in-law of producer Harry Saltzman. When she was younger she had wanted to be a screenwriter, so director André De Toth gallantly ceded his writing credit to her. Six weeks later she died from a brain tumor, but enjoyed her brief notoriety.
Nigel Davenport was first cast in a key supporting role, but upgraded to the second lead when Richard Harris was fired.
Richard Harris claims he quit after a furious row with producer Harry Saltzman. Harris' role was considerably changed after last-minute script revisions. His salary would have been £150,000, according to biographer Michael Feeney Callan.
Nigel Davenport was originally cast as Col. 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 was known as both "Written in the Sand" and "The Dynamiters" while in production.
According to Nigel Davenport, the reason Richard Harris was fired was because he refused a military-style haircut for the role of a British officer.