Mexican actor Pedro Armendáriz was recommended to Young by director John Ford to play Kerim Bey. After experiencing increasing discomfort on location in Istanbul, Armendáriz was diagnosed with inoperable cancer. Filming in Istanbul was terminated, the production moved to Britain, and Armendáriz's scenes were brought forward so that he could complete his scenes without delay. Though visibly in pain, he continued working as long as possible. When he could no longer work, he returned home and took his own life. Remaining shots after Armendáriz left London had a stunt double and Terence Young himself as stand-ins.