Location shooting took place around London including in Kensington, Belgravia, Northolt Aerodrome and Tower Bridge.

The Monthly Film Bulletin wrote: " Within its own limits, the story is quite competently handled, although the Iron Curtain trimmings begin to have a rather tired and jaded look.

The Tower of London sequence is rather reminiscent of a Hitchcock film of the 1930's, but the present director's ability to sustain a mood does not equal that of her predecessor.

The cast contains a wide variety of familiar English and un-English types, though some may feel that Margaret Leighton's wicked Helen is a little too much of a good thing.

"[4] The New York Times wrote, "an obvious fly-by-night, with a pretty good cast headed by the gifted Margaret Leighton and John Justin, this Associated Artists release is a slow, contrived and exasperatingly arch puzzler that sets some sort of record for meandering banality".