Margaret Lockwood
Frances Gray
Dane Clark
Bill Casey
Marius Goring
Commandant Anton Razinski
Naunton Wayne
Mr. Hedgerley
Wilfrid Hyde-White
Mr. Luke
Eugene Deckers
Alf
Olaf Pooley
Detective-Interrogator
Gladys Henson
Attendant
Paul Hardtmuth
Priest
Michael Hordern
Lab Director Owens
George Benson
Sandwich Stand Customer
Eric Pohlmann
Joe - the bartender
John Horsley
Customs Officer
Patric Doonan
Customs Man
Joan Haythorne
Judy
Jill Balcon
Wardress (uncredited)
Hyma Beckley
Café Mimosa Patron (uncredited)
John Boxer
Police Sergeant at Customs Café (uncredited)
Ernest Butcher
Tom - Lab Assistant (uncredited)
Daniel Brown
Train Passenger (uncredited)
Robert Cawdron
Soldier at Station Checkpoint (uncredited)
Anton Diffring
Officer at Station (uncredited)
Toni Frost
Stewardess (uncredited)
John Gabriel
Night Field Telephone Officer (uncredited)
Charles Hammon
Train Passenger in Platform Line-up (uncredited)
Philo Hauser
Waiter (uncredited)
John G. Heller
Soldier at Station Check Point (uncredited)
Noel Johnson
Frank Conway (uncredited)
Sam Kydd
Customs Man (uncredited)
Richard Marner
Soldier on Train (uncredited)
Louis Matto
Café Mimosa Waiter (uncredited)
Anthony Newley
Operator (uncredited)
Michael Ritterman
The ‘Tail’ (uncredited)
Lance Secretan
Alan (uncredited)
Dinah Sheridan
Train Passenger at Checkpoint (uncredited)
Ewen Solon
Enemy Scientist (uncredited)
Emile Stemmler
Soldier at Station Checkpoint (uncredited)
Robert Vossler
Day Sentry at First Checkpoint (uncredited)
John Wilder
Customs Officer (uncredited)
Billy Wilmot
Café Mimosa Customer (uncredited)
Roy Ward Baker
Director
Eric Ambler
Writer
Antony Darnborough
Producer
Earl St. John
Executive Producer
Richard Addinsell
Original Music Composer
Reginald H. Wyer
Director of Photography
Alfred Roome
Editor