Top Secret (U.S. title: Mr. Potts Goes to Moscow [2]; also known as Laughter behind the Curtain [3]) is a 1952 British black and white comedy film directed by Mario Zampi and starring George Cole, Oskar Homolka and Nadia Gray.

George Potts, a plumber in a top secret government research plant, accidentally comes into possession of the plans for a revolutionary atomic weapon.

The Monthly Film Bulletin wrote: "This heavily facetious little comedy is almost too silly to take seriously; yet one wonders if any good purpose is served by a series of schoolboy jokes directed against the U.S.S.R.

As one might expect from the authors of Laughter in Paradise, characterisation and incident stem from the hoariest traditions of British farce, and the technique of the film is theatrical.

"[7] The New York Times noted, "as long as the action stays this side of the Iron Curtain, the production is enjoyable – and understandable – but once entangled with the enigma of Communist rule, the farce ends.

Oscar Homolka fits naturally into the role of the Russian envoy who talks the Englishman into going to Moscow and who is eventually happy to join him on British territory.