Director Fritz Lang was disappointed in "Ministry of Fear" because the producer and screenwriter, Seton I. Miller, were the same person, and Miller the producer wouldn't let Lang rewrite his script, which Lang said "had practically none of the quality of the Graham Greene book."
Paramount paid Graham Greene £10,000 for the film rights to his novel, money he was very glad to have in wartime England. However, he was very disappointed in the film, especially as it had been directed by Fritz Lang, a film-maker he especially admired. Years later, Greene briefly met Lang, and the director made a point of apologizing to him for the film, by which Greene was touched.
Graham Greene's title, which goes unexplained in this film version, derives from a Wordsworth poem.
The character name "Hilfe" is also the German word for "help."
Forrester works for the Ministry of Home Security, a genuine British governmental department established in 1939 to defend the UK's civilian population against enemy action.