Donald Woods
— Juan Cesare
Margaret Lindsay
— Florence Ballau
C. Aubrey Smith
— Gerard Lytton
Henry O'Neill
— Victor Ballau
Robert Barrat
— Inspector Von Brinkner
Florence Fair
— Teresa
Frank Reicher
— Von Stein
Charles Judels
— Salvatore
Rafaela Ottiano
— Lili Salvatore
Paul Porcasi
— Antonio
Eily Malyon
— Fredericka
Egon Brecher
— Karl
Herman Bing
— Baker
Henry Kolker
— Auctioneer
Barlowe Borland
— Eric (uncredited)
Glen Cavender
— Detective (uncredited)
Wheaton Chambers
— Servant (uncredited)
Carlos De Valdez
— Conductor (uncredited)
Charles Fallon
— Apothecary (uncredited)
Betty Farrington
— Frieda (uncredited)
Olaf Hytten
— Scotland Yard Radio Operator (uncredited)
William Irving
— Policeman Schultz (uncredited)
Charles Lane
— Man in Front Row (archive footage)
Eric Mayne
— Bidder at Auction (uncredited)
William V. Mong
— Fishback (uncredited)
David Newell
— Rodrigo (uncredited)
Paul Panzer
— Detective (uncredited)
Russ Powell
— First Taxi Driver (uncredited)
Adrian Rosley
— Pasquale (uncredited)
Ferdinand Schumann-Heink
— Policeman Otto (uncredited)