Leslie Banks
Taylor
Michael Redgrave
Russian
Will Hay
Skipper
John Mills
Tom
Bernard Miles
Royal Navy Mate
Michael Rennie
George
Frank Cellier
Schneider
Robert Morley
Von Geiselbrecht
Alfred Drayton
Direktor
Marius Goring
German Propaganda Officer
Austin Trevor
U-boat Captain
Albert Lieven
Gunter
Leif Konow
Dane
John Stuart
Royal Navy: Naval Officer
Morland Graham
Civil Service
John Boxer
Press
Cyril Chamberlain
Press
Elliott Mason
German: German Stationmistress
George Merritt
German: German Shelter Marshal
Bernard Rebel
Quisling
George Woodbridge
Quisling
Ronald Adam
German businessman (uncredited)
Mark Daly
Driver (uncredited)
Thora Hird
German barmaid (uncredited)
Frederick Piper
Malta official (uncredited)
Ronald Shiner
Shipping clerk (uncredited)
Manning Whiley
Naval officer (uncredited)
Michael Wilding
Captain (uncredited)
John Williams
Voice over (uncredited)