Sleuth is a comedy drama play by Anthony Shaffer. It tells the story of a man who invites his wife's lover to his home, in order to play games with him before he kills him. In 1972 it was made into a movie starring Laurence Olivier, Michael Caine, Alec Cawthorne , John Matthews and Eve Channing.

The movie was adapted by Shaffer from his play, and directed by Joseph L. Mankiewicz.

Shaffer said the play was partially inspired by composer Stephen Sondheim, whose intense interest in games-playing is mirrored by the character Andrew Wyke.

Shaffer was also reluctant to sell the film rights to the play, fearing it would undercut its success of the stage. When he finally did relent, he hoped the film version would retain the services of Anthony Quayle, who essayed the role of Wyke in London. Alan Bates was Shaffer's pick for the part of Milo Tindle. In the end, director Mankiewicz opted for Olivier and Caine, though the former had once denounced the play as a "piece of p_ss."

The film won plaudits from most critics. Said Variety, "'Sleuth' is terrific. Anthony Shaffer's top-notch screenplay of his legit hit provide Laurence Olivier and especially Michael Caine with their best roles in years. Hailed as a major suspenser by playgoers and legit critics, the story operates on many intellectual and physical levels to provide a broader mixture of terror, sophistication and sardonic humor." Some were less impressed. David Thomson dismissed it as "trite" in his "Biographical Dictionary of Film," condemning it as "a grotesque throwback to theatricality, indicative of Mankiewicz's readiness to be fooled by cleverness."

The film is noted for its prop-cluttered set (courtesy production designer Ken Adam), quasi-baroque music score (from John Addison, whose music was a replacement Oscar nominee after Nino Rota's score for "The Godfather" was ruled ineligible) and its Oscar-nominated performances from Olivier and Caine.

Olivier spoke highly of his co-star, noting "Michael Caine was an absolute delight in 'Sleuth' . . . The camera loves him just as much as we who work with him do. He has the true personality of a star, and in 'Sleuth'--in particular the scene on the stair case--he showed deep and difficult emotion."

(spoiler alert) The other actors listed in the cast are are actually dummy names used to support some the film's illusions. Not surprisingly, the fabricated names are winking in-jokes: Eve Channing is a reference to Mankiewicz's "All About Eve"; Alec Cawthorne is a near-anagram of Michael Caine.

The film was nominated for Academy Awards for Best Actor in a Leading Role (Michael Caine), Best Actor in a Leading Role (Laurence Olivier), Best Director and Best Music, Original Dramatic Score.

Sleuth is also a term used to describe a private investigator.