Characters played by Richard Basehart
Joe Hamstringer
Characters played by Trevor Howard
Major Roger Court
Characters played by Alida Valli
Roberta Gleukovitch
Characters played by Eduardo Ciannelli
Dr. Vivaldi
Characters played by Richard O'Sullivan
Roger Court
Characters played by Stephen Murray
British Consul in Venice
Characters played by Arnoldo Foà
Commissioner
Characters played by Guido Celano
Chief Constable
Characters played by Giorgio Costantini
Pescovitch
Characters played by Angelo Cecchelin
Luza
Characters played by Nino Vechina
First Killer
Characters played by Armando Papette
Second Killer
Characters played by Giovanni Karuz
Third Killer
Characters played by Joan Butterfield
Mrs. Harrington
Characters played by Alessandro Paulon
Morgan
Characters played by Remington Olmsted
Ramondo
Characters played by Nerio Bernardi
Minor Role
Characters played by Helen Goss
Undetermined Role
Characters played by Jacopo Tecchi
Minor Role