The Sex Thief (U.S. title Her Family Jewels, Netherlands: Handful of Diamonds''') is a 1973 British sex comedy film directed by Martin Campbell and starring David Warbeck, Diane Keen and Christopher Biggins. The film was written by Tudor Gates and Michael Armstrong under the name Edward Hyde.

Plot

Grant Henry, a writer of trashy paperbacks like The Dirty and the Dying, moonlights as a masked jewel thief who is usually caught in the act but is able to get away with his crimes by luring his female victims to bed. After these women lie to the police about the thief's identity ("who could disguise himself as a clubfooted coloured midget one week and a 6′6″ Russian with a harelip the next") and seem to want to get burgled again, the Inspector in charge of the case and an insurance investigator trained in kung fu decide to lay a trap for the thief.