Principal Cast
Alec Guinness
as Professor Marcus
Cecil Parker
as Claude, alias Major Courtney
Herbert Lom
as Louis, alias Mr. Harvey
Peter Sellers
as Harry, alias Mr. Robinson
Danny Green
as One-Round, alias Mr. Lawson
Katie Johnson
as Mrs. Wilberforce
Jack Warner
as The Superintendent
Philip Stainton
as The Sergeant
Frankie Howerd
as The Barrow Boy
Madge Brindley
as Large Lady (uncredited)
Hélène Burls
as Hypatia (uncredited)
Kenneth Connor
as Cab Driver (uncredited)
Michael Corcoran
as Burglar (uncredited)
Harold Goodwin
as Parcels Clerk (uncredited)
Fred Griffiths
as Junk Man (uncredited)
Lucy Griffiths
as Miss Pringle (uncredited)
George Hilsdon
as Security Van Driver (uncredited)
Vincent Holman
as Station Master (uncredited)
Stratford Johns
as Security Guard (uncredited)
Sam Kydd
as Second Cab Driver (uncredited)
Edie Martin
as Lettice (uncredited)
Jack Melford
as Detective (uncredited)
Arthur Mullard
as (uncredited)
Ewan Roberts
as Constable (uncredited)
George Roderick
as Radio Car Policeman (uncredited)
John Rudling
as Nervous Man (uncredited)
Leonard Sharp
as Pavement Artist (uncredited)
Peter Williams
as Detective at Parcels Office (uncredited)
Neil Wilson
as Policeman (uncredited)
