According to 'Halliwells', this film when first released "was for obscure legal reasons hardly seen".
Eric Ambler's source 'Journey into Fear' novel is said to have greatly influenced 'Ian Fleming''s novel (and therefore also the film of) From Russia with Love (1963).
The character of Colonel Haki (played in this film by Joseph Wiseman who had been Dr. No (1962)) also appears in Eric Ambler's novel and film of The Mask of Dimitrios (1944) where Colonel Haki was played by Kurt Katch. In the original Journey Into Fear (1943), Colonel Haki was played by Orson Welles. Wiseman is the third and last person to date to play the character.
First major Hollywood production to be filmed in Vancouver, Canada.