Noted British actor Edmund Purdom overdubbed in English the lines of French-Lithuanian actor Jacques Sernas on the soundtrack of this film, due to Sernas not having a firm English-speaking voice. Sernas at that point in his career was learning English but had not yet mastered the language. Purdom was not credited with his voiceover talent for this picture, as the film's producers wanted the public to think Sernas did it all on his own.