George Cole
George Archibald Potts
Oskar Homolka
Zekov
Nadia Gray
Tania
Wilfrid Hyde-White
Sir Hubert Wells
Richard Wattis
Barnes
Irene Handl
Mrs. Tidmarsh
Christopher Lee
Russian Agent (uncredited)
Frederick Leister
Prime Minister
Frederick Valk
Rakov
Geoffrey Sumner
Pike
Ronald Adam
Barworth Controller
Edwin Styles
Barworth Superintendent
Kynaston Reeves
Barworth Director
Ernest Jay
Professor Layton
Michael Medwin
Smedley
Henry Hewitt
Minister of Health
Walter Horsbrugh
1st Cabinet Minister
Anthony Shaw
2nd Cabinet Minister
Tim Turner
1st Reporter
Gibb McLaughlin
Schoolmaster
Michael Balfour
Jersey Sailor
Hal Osmond
Jersey Waiter
Charles Goldner
Gaston
Ronnie Stevens
Aubrey
Eleanor Summerfield
Cecilia
Phyllis Morris
Mrs. Tweedy
Myrtle Reed
Jersey Air Hostess
Ina De La Haye
Madame
David Hurst
Deutsch
Bernard Rebel
Trubiev
Olaf Pooley
Roblettski
Guido Lorraine
1st M.V.D.
Terence Alexander
2nd M.V.D.
Richard Marner
Russian Sentry
Martin Boddey
Russian Security Officer
Gerard Heinz
Russian Director of Plant
Fred Berger
Russian Doctor
Victor Maddern
British N.C.O.
Reed De Rouen
1st U.S. Soldier
Johnny Catcher
2nd U.S. Soldier
Willoughby Gray
British Officer
Anton Diffring
Border Police GDR (uncredited)