Bernard Lee
— Det. Supt. Meredith
Alexander Knox
— Colonel Calderwood
Moira Redmond
— Diana Marsh
William Russell
— Mike Stafford
Richard Vernon
— John Crewe
Richard Warner
— Mark Speller
John Gabriel
— Monet
Jack Rodney
— Gregory
Stanley Morgan
— Det. Sgt. Anson
Robert Percival
— Mr. Britton
Ann Harriman
— Receptionist
Julie Shearing
— Judy
Fanny Carby
— Mrs. Wall
Ian Hamilton
— Waiter
Walter Horsbrugh
— Registrar