The British Alibi is based on the warhorse story by Marcel Archard, previously filmed in France in 1931. Raymond Lovell steps into the old Erich Von Stroheim role as Professor Winkler, a phony mystic playing to capacity crowds in Paris. Confronting a man who'd previously exposed him as a fraud in the US, Winkler kills the man. He then establishes an alibi by paying nightclub hostess Helene (Margaret Lockwood) to tell the police that she was in his company at the time of the murder. The upshot of this is that Helene herself is accused of the crime. Hoping to get to the truth of the matter, Inspector Calas (Hugh Sinclair) asks his deputy Andre Laurent (James Mason) to pretend to be in love with Helene. The plot thickens when Laurent genuinely falls for the distressed damsel. ~ Hal Erickson, Rovi