House of Blackmail is a 1953 British second feature[1] drama film directed by Maurice Elvey and starring Mary Germaine, William Sylvester and Alexander Gauge.

She drives to Markham's country house and en route picks up hitchhiker Jimmy, who agrees to pose as her lawyer.

Kine Weekly said "The picture ... opens well, but as soon as it moves to Markham’s mansion its action becomes a trifle stilted, Mary Germaine, as Carol, displays good looks and obvious acting ability, and William Sylvester, although a little too sure of himself, registers as Jimmy, but the rest are a very mixed bag.

The police cannot be called in, as the house is surrounded by a high-tension circuit, and someone removed at least 18 inches from the telephone wire, so we have to spend about 40 minutes finding out.

We could do with more surprises, but the pace is unrelenting and there are typically solid performances from Mary Germaine, William Sylvester and John Arnatt.