Trivia

Several books on Sir Michael Caine have alleged that the cast and crew were not paid because of cash problems. Caine admitted this in his 1992 autobiography "What's It All About?"

Jack Hawkins, who had lost his voice in 1966, was dubbed by Charles Gray.

This version covers both the novel "Kidnapped" and the first half of its sequel "Catriona".

Michael Caine wrote in his autobiography, he realized after three months of filming, that the film would be a failure. He was smoking about four packs of cigarettes a day, and drinking heavily, and decided to take a break in the countryside.

Jack Hawkins couldn't speak and had to have his voice dubbed because he had been operated on for throat cancer and has had a tracheotomy. This is also the reason why in every scene he wears a scarf, it obscures the site of the tracheotomy. He made several other films during this period where the same method of concealing the tracheotomy site is used.