Trevor Howard as Captain Thompson

José Ferrer as Major Stringer

Anthony Newley as Marine Clarke

Victor Maddern as Sgt. Craig

Percy Herbert as Marine Lomas

David Lodge as Marine Ruddock

Peter Arne as Marine Stevens

Graham Stewart as Marine Booth

John Fabian as Marine Cooney

John Van Eyssen as Marine Bradley

Robert Desmond as Marine Todd

Walter Fitzgerald as Gestapo Comdt.

Karl Stepanek as Assistant Gestapo Officer

Dora Bryan as Myrtie

Beatrice Campbell as Mrs Ruddock

Sydney Tafler as Policeman

Christopher Lee as Submarine Commander Alan Grieves

Pat McGrath as Marine Bellamy (uncredited)

Jack Carter as Soldier (uncredited)