Terence Morgan

as Inspector Ralph Brown

Yolande Donlan

as Jill Wilson

Anthony Oliver

as Inspector Newcombe

André Morell

as Robert Isaac Pitt

Reginald Beckwith

as Harold

Ursula Howells

as Antonia Pitt

Guido Lorraine

as Pietr Revski

Basil Dignam

as Wing Commander Riddle

Raymond Rollett

as Sir Robert Rosper

Fred Johnson

as Professor Robinson-Heston

Arnold Marlé

as Karl Kopek

Mark Dignam

as Prison Governor

John Horsley

as Assistant Commissioner

Barry Lowe

as Eric Colter

Diana Lambert

as Young Woman

Petra Davies

as Pitt's Maid (uncredited)

Brown Derby

as Police Sergeant (uncredited)

Michael Godfrey

as Chertwell Security Guard (uncredited)

Arthur Lovegrove

as Nick (uncredited)

Louis Matto

as Waiter (uncredited)

Guy Mills

as Brown's Driver (uncredited)

Stuart Mitchell

as Head Waiter (uncredited)

Jim Brady

as Nick's Thug (uncredited)

Cyril Renison

as Detective Sergeant Enders (uncredited)