Contraband (1940) is a wartime spy film by the British director-writer team of Michael Powell and Emeric Pressburger, which reteamed stars Conrad Veidt and Valerie Hobson after their success in The Spy in Black the previous year. Veidt plays a hero, something he did not do very often. There is also an early uncredited performance by Leo Genn.
The title of the film in the United States was Blackout. Powell is quoted in his autobiography, A Life in Movies, as saying that the US renaming was a better title and he wished he had thought of it.
(Summary from Wikipedia)