Boris Karloff

Colonel March Of Scotland Yard

Ewan Roberts

Inspector Ames

Phil Brown

Dr. Bryan Hayes

Eric Pohlmann

The Emir

Patrick Barr

Horton

Russell Waters

Hocksby

Alan Wheatley

O'Brien

Olaf Pooley

Carlmeddy

Hubert Gregg

Pennacott

Rosalie Crutchley

Annette

Richard O'Sullivan

Roger

Eliot Makeham

1st Judge

Mary Clare

Mrs. Wrigley

Zena Marshall

Madeleine

Patricia Owens

Betty Hartley

George Coulouris

Harwood

John Hewer

John Parrish

Elspet Gray

Johanna

Anthony Newley

Ned

Glyn Houston

Peter Ridgway

Christopher Lee

Jeanpierre

Rachel Gurney

Martha

Tony Wright

Terry Fortescue / Henry Fortescue

Richard Wattis

Arthur Cabot

Peter Dyneley

Red Darrow

Laurence Payne

Delius

Lionel Murton

Crowder

Alec Mango

Narbu

Michael Shepley

Sir Nigel

Marne Maitland

Waiter

Nora Gordon

Housekeeper

Peter Illing

Lavois

Joan Sims

Marjorie Dawson

Tommy Duggan

Lawton

John Laurie

Dr. Brandeis

Dana Wynter

Francine Rapport

John Arnatt

Wesley

Hugh Griffith

Dr. Ivy

Adrienne Corri

Clara

Patrick Holt

Paul

Doris Hare

Lydia

Rachel Kempson

Helen Rune

Arthur Hill

Jerry

Bruce Seton

Capt. Hartnett (uncredited)

Robert Brown

Hastings

Sheila Burrell

Joan Forsythe

Robert Ayres

Wyatt

Sandra Dorne

Rosie

Alfred Burke

Minister

Anton Diffring

Francois

Ronald Leigh-Hunt

Ireton Boulder

Eugene Deckers

Phillipe

Patricia Laffan

Jane

Hugh Williams

Harold Hartley

Patricia Marmont

Marion

Martin Benson

Dupont

Peter Asher

Andrew

Michael Alexander

Dr. Walker

Lloyd Lamble

Kane