Robert Beatty
Bob Beacham
Acting
Rona Anderson
Mary Game
Acting
Clifford Evans
Tom Harmon
Acting
Edward Lexy
Det. Insp. Charlton
Acting
Olga Lindo
Olive Tavy
Acting
Daphne Padel
Self - The Twenty Questions Team
Acting
Jeanne De Casalis
Self - The Twenty Questions Team guest artiste
Acting
Jack Train
Self - The Twenty Questions Team
Acting
Stewart MacPherson
Self - The Twenty Questions Team
Acting
Norman Hackforth
Self - The Twenty Questions Team 'Mystery Voice'
Acting
Richard Dimbleby
Self - The Twenty Questions Team
Acting
Harold Scott
Maurice Emery KC
Acting
Liam Redmond
Echo News editor
Acting
Homi Bode
Mohammed Ali
Acting
Kynaston Reeves
Gen. Maitland
Acting
Sonya O'Shea
Stewart MacPherson's secretary
Acting
Frederick Leister
Police Commissioner
Acting
Wally Patch
Police Officer 'Tiny' White
Acting
John Salew
John Grimshaw
Acting
Gordon McLeod
Record News editor
Acting
Philip King
Cheshire Cheese waiter
Acting
Arthur Young
Doctor
Acting
Merle Tottenham
Mrs. Tavy's Neighbour (uncredited)
Acting
Meadows White
Frederick 'Ricky' Tavey (uncredited)
Acting