Donald Pleasence

Character: Dr. Hawley Harvey Crippen

Coral Browne

Character: Belle Crippen

Samantha Eggar

Character: Ethel Le Neve

Donald Wolfit

Character: R.D. Muir (as Sir Donald Wolfit)

James Robertson Justice

Character: Captain McKenzie

Geoffrey Toone

Character: Mr. Tobin

Douglas Bradley-Smith

Character: Dr. Pepper

Olga Lindo

Character: Mrs. Clara Arditti

Elspeth March

Character: Mrs. Jackson

Paul Carpenter

Character: Bruce Martin

John Arnatt

Character: Chief Inspector Dew

Oliver Johnston

Character: Lord Chief Justice

John Lee

Character: Harry

Edward Underdown

Character: The Governor

Hamilton Dyce

Character: Dr. Rogers

Basil Henson

Character: Mr. Arditti

Totti Truman Taylor

Character: Miss Curnow

Edward Cast

Character: Harding

Colin Rix

Character: Chemist

Terence Brook

Character: Police Sergeant Outside Courtroom (uncredited)

Eric Dodson

Character: Defence QC Clerk (uncredited)

Max Faulkner

Character: Radio Officer Andrews (uncredited)

Guy Standeven

Character: Ships Steward (uncredited)

John Tatham

Character: Courtroom Spectator (uncredited)