Jack Warner

Inspector Peterson

Nadia Gray

Kara Niemann

John McCallum

Dr. Nils Ahlen

Anthony Dawson

Sven Nystrom

Mary Laura Wood

Helga Ahlen

Naima Wifstrand

Baroness Erland

Norman MacOwan

McTavis, ferry pilot

Christopher Lee

Det. Holt

Alfred Maurstad

Trerik

Martin Boddey

Chief of the Lost Valley

Ewen Solon

Det. Anderson

Gösta Cederlund

Prof. Lind

Sten Lindgren

Director-General of the Reasearch Institution

Peter Blitz

Anders

Fritiof Billquist

Colonel Strand (uncredited)

Sarah Crawford

Noma (uncredited)

Molly Warner

Frau Lind (uncredited)

George Willoughby

Bertil (uncredited)