Trivia

The film reunited a 1960's "mythical couple' Alain Delon and Romy Schneider. Schneider had dramatically broken-up with Delon couple years earlier and married German director and actor Harry Meyen in Berlin. She had a child. Delon insisted on her being cast, threatening to quite the film if she wasn't, despite producer Gérard Beytout's misgivings, as he was dubious about the actress from the Sissi (1955) trilogy in a bikini. Delon continuously pursued her, both before and after filming, with persistent attempts to reconcile. Despite Schneider's refusals, their shared history and emotional connection spilled onto the screen, infusing the film with raw authenticity. This genuine emotional backdrop, rooted in their real-life relationship, transcended the film's narrative, elevating it beyond its initial reception. While the original film may not have garnered universal acclaim, its enduring appeal lies in the palpable chemistry and complex emotions brought by Delon and Schneider.

Alain Delon said in an interview in 2011 that he cannot watch this film again. His ex-lover Romy Schneider and good friend Maurice Ronet both died prematurely and under tragic circumstances. Revisiting the scenes was simply too painful for him.

Both French and English-language versions of the film were made, with the actors filmed speaking English for the international release, which was unusual at a time when movies were always either dubbed or subtitled. That 114-minute international release, shorter than the French version, also had slightly different editing and differences such as Romy Schneider wearing a bikini top in the English version in scenes where she is topless in the French version.

During the making of this film, Alain Delon's former bodyguard, Stephan Markovic, was found dead in a public dump, ushering the "Markovic Affair." Markovic's brother started a feud with Alain Delon and his friends, one of whom was the French President, Georges Pompidou. Both Delon and his long-standing friend François Marcantoni were questioned by the police immediately after the murder. Marcantoni was originally charged for the murder, but after further questioning by the police, he was released. Later, the drama continued when supposedly inappropriate photos of Madame Pompidou were found. Commissionaire Aimé-Blanc, who was involved in the obtaining of the photos, stated that the photos were planted by old Gaullist clans who had long-term tension against Pompidou. This led to controversy over whether the photos were real. The murder of Markovic was never solved. There were plenty people who had the motive to kill him. He was a major gambler and created many enemies because of the recurring theory that he would cheat. In addition, Markovic was specially known for throwing high-class parties with Delon. At these parties, it is alleged that Markovic would set up cameras throughout the house, especially in the bedrooms. He gathered plenty of questionable photos of the guests, which would damage their status in society. These photos most likely were used as blackmail, especially when he approached multiple newspapers trying to sell the photographs. Surprisingly, some of these photos were alleged to be directly targeting Delon and Marcantoni. However, the most important photos Markovic supposedly had were scandalous photos of Pompidou's wife. This was a major concern to Pompidou since he was preparing to run for France's president. Alain Delon communicated with more gangsters, such as Z, Bimbo, and Petit René. Suspiciously, many of them met violent deaths after meeting Delon. However, François Marcantoni was Delon's closest Corsican gangster friend. When Delon's bodyguard, Markovic, mysteriously died, Marcantoni and Delon came under investigation. One of the factors pointing in that direction was a letter of Stephan Markovic to his brother Aleksandar, where he wrote: "If I get killed, it's 100% fault of Alain Delon and his godfather Francois Marcantoni." Marcantoni was initially charged with the murder. However, after being questioned by the police, the charges were eventually dropped and the crime was never solved. As of 2016, Delon is the only member left of the Markovic affair to be still alive.

Harry's car is a Maserati Ghibli released in 1967. The screenwriter had planned to use a Lamborghini Espada but Maserati French's official merchandiser convinced the producers to use a Ghibli instead.