Robert Beatty

as Dr. Mark Benton

Elizabeth Sellars

as Della Freeman

Peter Coke

as Det. Insp. George Bellamy

Hugh Kelly

as Dr. Craig

Vida Hope

as Jackie Leroy

Janet Butler

as Sister Rogers

Ferdy Mayne

as Charles Constance

James Raglan

as Supt. Grayson

Hugh Pryse

as Mr. Rattray

George Benson

as Prescott

Roger Delgado

as Felix Galegos

Frank Atkinson

as Railway Ticket Clerk (uncredited)

Donald Conlon

as Helios Restaurant Patron (uncredited)

Arthur Dibbs

as Helios Restaurant Patron (uncredited)

Robert Gregory

as Man at Northolt Airport (uncredited)

Jean Hardwicke

as Sister (uncredited)

Barry Johns

as Hospital Orderly (uncredited)

Anthony Lang

as Johnny (uncredited)

Ronald Leigh-Hunt

as Sgt. Lewis (uncredited)

Richard Neller

as Hospital Visitor (uncredited)

Harold Sanderson

as Hospital Visitor (uncredited)

Marc Sheldon

as Waiter (uncredited)

Toke Townley

as Fred Barker (uncredited)