While making a movie on the French Riviera, the producer Max Poulton has been having an affair with his star, Gina Bertini. A married man, Max does not want to lose his wife Carol, but the hot-tempered Gina threatens to tell all.
Max comes home with a blood stain on his shirt cuff. A visit follows from an Inspector Carliss of Scotland Yard, who says Gina's body has just been found, stabbed to death.
Rushing to the house where he and Gina used to secretly meet, Max gathers up possessions he's left behind. A neighbor spots his car. Upon returning home, to a party Carol is hosting, Max is astounded to find Gina alive and well among the guests.
Confused, he drives her home, leaves her in the car briefly, then returns to find her lifeless body, once again stabbed. Max thinks he must be losing his mind. This time a local police official, Inspector Simon, comes to call. The only conclusion Max can draw is that Carliss is somehow trying to frame him.
His suspicions are correct. Carliss is not a Scotland Yard inspector at all but Gina's jealous ex-husband. He has arranged things to make Max appear guilty, and Simon, having the neighbor's eyewitness description of seeing Max's car, has little choice but to place Max under arrest.
When it looks as though Carliss intends to harm Carol as well, Max escapes from jail. He manipulates Carliss into stealing his own car, and when the police give chase to the wrong man, Carliss, in a panic, drives over a cliff. Max's innocence becomes apparent to the police.Stewart Granger as Max Poulton
Donna Reed as Carol Poulton
George Sanders as Carliss
Gianna Maria Canale as Gina Bertini
Michael Shillo as Inspector Simon
Richard Molinas as Gilbert
Peter Dyneley as Willy Reichel
John Van Eyssen as Archer
Philip Vickers as Jack Leslie
Jimmy Thompson as Assistant
Hy Hazell as American Woman
Philip Mackie's 90-minute play debuted on television, airing on the BBC. It was then turned into a stage play which was presented by Henry Sherrek in London in October 1955. Reviewing it Kenneth Tynan said the first two acts were "the tautest puzzle play since Dial M for Murder" but did not like the ending. The US rights and film rights were bought by Gilbert Miller. The TV play was screened again in 1956.
The film was made by Romulus Productions. Stewart Granger had just finished his contract with MGM and signed a two-picture deal with Romulus, of which The Whole Truth was to be the first; the second was to be The Night Comers from a novel by Eric Ambler and co-starring Jean Simmons. (This movie was never made.)
Jeanne Crain was originally announced as the female lead. However Donna Reed ended up playing it.
Filming started in London on 16 September 1957.
Romulus later announced they offered Stewart Granger a six-picture contract worth $1.5 million However he made no more films for that company.