Quiz

Although his film is close to Pierre Lesou's novel, director Yves Boisset confessed that, during the scene between Michel Constantin and Michel Bouquet, he was influenced by Jean-Pierre Melville's films' atmosphere and dialogue.

Lino Ventura was offered the role of inspector Favenin, but turned it down, finding the character too unpleasant.

Then French Minister of the Interior Raymond Marcellin saw the film as violent anti-police propaganda and campaigned hard for it to be banned. After a two-hour debate on July 30th 1970, the Classification Commission voted to approve the film without cuts and restrict it to over 13-year-olds and a release date was set for September 16th. Under pressure from Marcellin, the Minister of Culture Edmond Michelet didn't sign the theatrical release visa and instead sent the film back for another vote, where Marcellin demanded that eighteen minutes be cut, including all scenes featuring Adolfo Celi, the interrogation scene and some dialogue, which director Yves Boisset refused. Eventually, some lines were cut, the interrogation scene was reshot and the film was finally approved for release. Internationally, the film was released uncut but it remains censored in France, with the original interrogation scene only available as a bonus feature on home video. Ironically, Boisset believes that all the controversy contributed heavily to the film's success and that Marcellin was the best publicist he ever had.

Producer Véra Belmont was prosecuted for using her underage son Stéphan Holmes in a scene that the French child services deemed inappropriate.

Final film of Anne Carrère.