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Jack Warner as Inspector Peterson |
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Nadia Gray as Kara Niemann |
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John McCallum as Dr. Nils Ahlen |
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Anthony Dawson as Sven Nystrom |
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Mary Laura Wood as Helga Ahlen |
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Naima Wifstrand as Baroness Erland |
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Norman MacOwan as McTavis, ferry pilot |
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Christopher Lee as Det. Holt |
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Alfred Maurstad as Trerik |
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Martin Boddey as Chief of the Lost Valley |
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Ewen Solon as Det. Anderson |
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Gösta Cederlund as Prof. Lind |
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Sten Lindgren as Director-General of the Reasearch Institution |
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Peter Blitz as Anders |
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Fritiof Billquist as Colonel Strand (uncredited) |
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Sarah Crawford as Noma (uncredited) |
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Molly Warner as Frau Lind (uncredited) |
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George Willoughby as Bertil (uncredited) |
| Production | Nat A. Bronstein | Producer |
| Camera | Harry Waxman | Director of Photography |
| Sound | Nino Rota | Original Music Composer |
| Writing | Terence Young | Writer |
| Directing | Terence Young | Director |
| Camera | James Bawden | Camera Operator |
| Writing | Nat A. Bronstein | Original Story |
| Sound | Graeme Hamilton | Sound Editor |
| Directing | Basil Keys | Assistant Director |
| Crew | Arthur Alcott | Production Controller |
| Costume & Make-Up | George Blackler | Makeup Artist |
| Editing | Lito Carruthers | Editor |
| Sound | Muir Mathieson | Music Director |
| Writing | Paul Tabori | Original Story |
| Art | J. Elder Wills | Art Direction |
