Trailer
Images
 | George Cole as George Archibald Potts |
 | Oskar Homolka as Zekov |
 | Nadia Gray as Tania |
 | Wilfrid Hyde-White as Sir Hubert Wells |
 | Richard Wattis as Barnes |
 | Irene Handl as Mrs. Tidmarsh |
 | Christopher Lee as Russian Agent (uncredited) |
 | Frederick Leister as Prime Minister |
 | Frederick Valk as Rakov |
 | Geoffrey Sumner as Pike |
 | Ronald Adam as Barworth Controller |
 | Edwin Styles as Barworth Superintendent |
 | Kynaston Reeves as Barworth Director |
 | Ernest Jay as Professor Layton |
 | Michael Medwin as Smedley |
 | Henry Hewitt as Minister of Health |
 | Walter Horsbrugh as 1st Cabinet Minister |
| Anthony Shaw as 2nd Cabinet Minister |
 | Tim Turner as 1st Reporter |
 | Gibb McLaughlin as Schoolmaster |
 | Michael Balfour as Jersey Sailor |
 | Hal Osmond as Jersey Waiter |
| Charles Goldner as Gaston |
 | Ronnie Stevens as Aubrey |
 | Eleanor Summerfield as Cecilia |
| Phyllis Morris as Mrs. Tweedy |
| Myrtle Reed as Jersey Air Hostess |
 | Ina De La Haye as Madame |
 | David Hurst as Deutsch |
| Bernard Rebel as Trubiev |
 | Olaf Pooley as Roblettski |
 | Guido Lorraine as 1st M.V.D. |
 | Terence Alexander as 2nd M.V.D. |
 | Richard Marner as Russian Sentry |
 | Martin Boddey as Russian Security Officer |
 | Gerard Heinz as Russian Director of Plant |
| Fred Berger as Russian Doctor |
 | Victor Maddern as British N.C.O. |
| Reed De Rouen as 1st U.S. Soldier |
| Johnny Catcher as 2nd U.S. Soldier |
 | Willoughby Gray as British Officer |
 | Anton Diffring as Border Police GDR (uncredited) |
| Directing | |
| Mario Zampi | Director |
Writing | |
| Michael Pertwee | Screenplay |
| Jack Davies | Screenplay |
Sound | |
| Stanley Black | Original Music Composer |
Camera | |
| Stanley Pavey | Director of Photography |
Art | |
| Ivan King | Art Direction |
Editing | |
| Giulio Zampi | Editor |
Production | |
| Mario Zampi | Producer |
