Humphrey Bogart was involved in a serious automobile accident during production of this film, which knocked out several of his teeth and hindered his ability to speak. John Huston reportedly hired a young British actor noted for his mimicry skills to rerecord some of Bogart's spoken lines during post-production looping. Although it is undetectable when viewing the film today, it is Peter Sellers who provides Bogart's voice during some of the scenes in this movie. However this cannot be confirmed.
This was the fifth and last movie that Humphrey Bogart would make with Peter Lorre. The other four were, The Maltese Falcon (1941), Casablanca (1942), All Through the Night (1942), and Passage to Marseille (1944).
Humphrey Bogart said of Truman Capote, "He wrote like fury. He had the damnedest and most upside-down slant on humor you've ever heard."
Humphrey Bogart reportedly disliked the film, perhaps because he lost a good deal of his own money bankrolling it.