Professor Marcus
Alec Guinness
Claude, alias 'Major Courtney'
Cecil Parker
Hypatia (uncredited)
Hélène Burls
Cab Driver (uncredited)
Kenneth Connor
Burglar (uncredited)
Michael Corcoran
Parcels Clerk (uncredited)
Harold Goodwin
Junk Man (uncredited)
Fred Griffiths
Miss Pringle (uncredited)
Lucy Griffiths
Security Van Driver (uncredited)
George Hilsdon
Station Master (uncredited)
Vincent Holman
Security Guard (uncredited)
Stratford Johns
Second Cab Driver (uncredited)
Sam Kydd
Louis, alias 'Mr. Harvey'
Herbert Lom
Lettice (uncredited)
Edie Martin
Detective (uncredited)
Jack Melford
(uncredited)
Arthur Mullard
Constable (uncredited)
Ewan Roberts
Radio Car Policeman (uncredited)
George Roderick
Nervous Man (uncredited)
John Rudling
Pavement Artist (uncredited)
Leonard Sharp
Detective at Parcels Office (uncredited)
Peter Williams
Policeman (uncredited)
Neil Wilson
Constance (uncredited)
Phoebe Hodgson
Harry, alias 'Mr. Robinson'
Peter Sellers
'One-Round', alias 'Mr. Lawson'
Danny Green
Mrs. Wilberforce
Katie Johnson
The Superintendent
Jack Warner
The Sergeant
Philip Stainton
The Barrow Boy
Frankie Howerd
Large Lady (uncredited)
Madge Brindley
Assistant Editor
Jim Clark
Assistant Director
Tom Pevsner
Original Music Composer
Tristram Cary
Director of Photography
Otto Heller
Screenplay
William Rose
Story
Director
Alexander Mackendrick
Associate Producer
Seth Holt
Producer
Michael Balcon
Editor
Jack Harris
Jimmy O'Connor
Special Effects
Sydney Pearson
Music Director
Dock Mathieson
Production Supervisor
Hal Mason
Assistant Art Director
Bert Davey
Set Designer
Jack Shampan
Camera Operator
Chic Waterson
Art Direction
Jim Morahan
Costume Design
Anthony Mendleson
First Assistant Camera
Alan Bryce
Scenic Artist
W. Simpson Robinson
Unit Production Manager
David Peers
Makeup Artist
Alex Garfath
Tony Rimmington
Ray Parslow
Herbert Smith
Harry Aldous
Norman Dorme
Color Timer
Joan Bridge
Hairstylist
Daphne Martin
Supervising Sound Editor
Stephen Dalby
Continuity
Felicia Manheim
Sound Recordist
Leo Wilkins
Sound Editor
Gordon Stone
Robin Clarke