George Murphy
Inspector James 'Jim' Belden
Acting
Finlay Currie
Professor Albert Kafer
Acting
Virginia Gilmore
Millie / Teresa Zalenko
Acting
Karl Stepanek
Alexi Laschenkov / Gregory Anders
Acting
Louisa Horton
Mrs. Elaine Wilben
Acting
Peter Capell
Chris Zalenko / Gino
Acting
Bruno Wick
Luther Danzig
Acting
Vilma Kurer
Mrs. Rita Foss
Acting
Ann Thomas
Philadelphia Suspect
Acting
George Roy Hill
Nicholas Wilben
Directing
Karl Weber
FBI Agent Charlie Reynolds
Acting
Michael Garrett
Michael Dorndoff aka Frank Torrance
Acting
Lotte Palfi Andor
Anna Kafer
Acting
Ernest Graves
Robert Martin
Acting
Robert Carroll
Boldany
Acting
Wolfgang Zilzer
August Helmuth
Acting
Bradford Hatton
Harry Mason
Acting
Rosemary Pettit
Mrs. Martin
Acting
Eva Condon
Landlady
Acting
Steve Mitchell
Samson
Acting
John Farrell
Taxi Driver (uncredited)
Acting
Nancy Hale
Mrs. Belden (uncredited)
Acting
Westbrook Van Voorhis
Narrator (voice) (uncredited)
Acting
Mary Young
Old Lady (uncredited)
Acting
Suzanne Moulton
Sherry Belden (uncredited)
Acting