PARIS — The French writer Gabriel Matzneff never hid the fact that he engaged in sex with girls and boys in their early teens or even younger. He wrote countless books detailing his insatiable pursuits and appeared on television boasting about them. “Under 16 Years Old,” was the title of an early book that left no ambiguity.

Still, he never spent a day in jail for his actions or suffered any repercussion. Instead, he won acclaim again and again. Much of France’s literary and journalism elite celebrated him and his work for decades. Now 83, Mr. Matzneff was awarded a major literary prize in 2013 and, just two months ago, one of France’s most prestigious publishing houses published his latest work.

But the publication, last Thursday, of an account by one of his victims, Vanessa Springora, has suddenly fueled an intense debate in France over its historically lax attitude toward sex with minors. It has also shone a particularly harsh light on a period during which some of France’s leading literary figures and newspapers — names as big as Foucault, Sartre, Libération and Le Monde — aggressively promoted the practice as a form of human liberation, or at least defended it.

A day after the publication of Ms. Springora’s book, “Le Consentement,” or “Consent,” which sold out quickly at many Paris bookstores, the fallout continued. Prosecutors in Paris announced that after “analyzing” its contents, they had opened an investigation into the case and would also look for other victims in and out of France.