Bob Beacham

Robert Beatty

Acting

Mary Game

Rona Anderson

Acting

Tom Harmon

Clifford Evans

Acting

Det. Insp. Charlton

Edward Lexy

Acting

Olive Tavy

Olga Lindo

Acting

Self - The Twenty Questions Team

Daphne Padel

Acting

Self - The Twenty Questions Team guest artiste

Jeanne De Casalis

Acting

Self - The Twenty Questions Team

Jack Train

Acting

Self - The Twenty Questions Team

Stewart MacPherson

Acting

Self - The Twenty Questions Team 'Mystery Voice'

Norman Hackforth

Acting

Self - The Twenty Questions Team

Richard Dimbleby

Acting

Maurice Emery KC

Harold Scott

Acting

Echo News editor

Liam Redmond

Acting

Mohammed Ali

Homi Bode

Acting

Gen. Maitland

Kynaston Reeves

Acting

Stewart MacPherson's secretary

Sonya O'Shea

Acting

Police Commissioner

Frederick Leister

Acting

Police Officer 'Tiny' White

Wally Patch

Acting

John Grimshaw

John Salew

Acting

Record News editor

Gordon McLeod

Acting

Cheshire Cheese waiter

Philip King

Acting

Doctor

Arthur Young

Acting

Mrs. Tavy's Neighbour (uncredited)

Merle Tottenham

Acting

Frederick 'Ricky' Tavey (uncredited)

Meadows White

Acting