Suspect
Cast
Murray Melvin
Teddy Boy
Tony Britton
Dr. Robert Marriott
Virginia Maskell
Dr. Lucy Byrne
Donald Pleasence
Parsons, alias Bill Brown
John Payne
Iverson
Geoffrey Bayldon
Rosson
Ian Bannen
Alan Andrews
Thorley Walters
Special Agent Prince
Raymond Huntley
Sir George Gatting the Minister of Defense
Sam Kydd
Slater
Spike Milligan
Arthur, lab orderly
Anthony Booth
Parkin
Basil Dignam
Dr Childs
Ian Wilson
Pin Table Man
Kenneth Griffith
Dr Shole
Peter Cushing
Professor Sewell
Brian Oulton
Director
Andre Charisse
Heller
Margaret Lacey
Prince's Secretary