Sixty years after the French Nobel laureate Albert Camus died in a car crash at the age of 46, a new book is arguing that he was assassinated by KGB spies in retaliation for his anti-Soviet rhetoric.

Italian author Giovanni Catelli first aired his theory in 2011, writing in the newspaper Corriere della Sera that he had discovered remarks in the diary of the celebrated Czech poet and translator Jan Zábrana that suggested Camus’s death had not been an accident. Now Catelli has expanded on his research in a book titled The Death of Camus.

Camus died on 4 January 1960 when his publisher Michel Gallimard lost control of his car and it crashed into a tree. The author was killed instantly, with Gallimard dying a few days later. Three years earlier, the author of L’Étranger (The Outsider) and La Peste (The Plague) had won the Nobel prize for “illuminat[ing] the problems of the human conscience in our times”.

“The accident seemed to have been caused by a blowout or a broken axle; experts were puzzled by its happening on a long stretch of straight road, a road 30 feet wide, and with little traffic at the time,” Herbert Lottman wrote in his 1978 biography of the author.

Catelli believes a passage in Zábrana’s diaries explains why: the poet wrote in the late summer of 1980 that “a knowledgeable and well-connected man” had told him the KGB was to blame. “They rigged the tyre with a tool that eventually pierced it when the car was travelling at high speed.”

Until today, everyone thought Camus had died because of an ordinary car crash. The man refused to tell me his source but he claimed it was completely reliable Jan Zábrana's diaries, 1980

The order, he said, had been issued by Dmitri Shepilov, a senior Soviet politician, in retaliation for an article by Camus in the French newspaper Franc-Tireur published in March 1957.

“It seems it took the intelligence three years to carry out the order,” Zábrana’s diary reports. “They managed eventually and in such a way that, until today, everyone thought Camus had died because of an ordinary car crash. The man refused to tell me his source but he claimed it was completely reliable.”

Camus had sided publicly with the Hungarian uprising since autumn 1956, and was highly critical of Soviet actions. He also publicly praised and supported the Russian author Boris Pasternak, who was seen as anti-Soviet.

Catelli has spent years researching the validity of Zábrana’s account. In his book, he interviews Zábrana’s widow Marie, investigates the KGB’s infiltration of France, and includes secondhand testimony from the controversial French lawyer Jacques Vergès. Catelli was contacted by Giuliano Spazzali, an Italian barrister, after the book’s publication in Italy. Spazzali recounted a conversation he’d had with the late Vergès about Camus’ death.

“Vergès said the accident had been staged. It is my opinion that Vergès had more evidence than he cared to share with me. I refrained from asking,” Spazzali told Catelli. “Discretion is the best attitude when a hot topic rises unexpectedly. I didn’t investigate any further, and yet I remember how Vergès was certain that the staged accident was schemed by a KGB section with the endorsement of the French intelligence.”

Catelli argues that Camus’ outspokenness was interfering with French-Soviet relations, and “Camus’ prominent character … stood out in the eyes of the French people as a reminder of the USSR’s cruel imperialism. Both the French and the Soviet governments would have benefited greatly from silencing this unpleasant reminder … No proper investigation was carried out.”

Catelli’s said his theory had not been endorsed by Camus’ daughter Catherine, who prohibited publisher Gallimard from quoting her father’s work. The book has nonetheless been published in France, Argentina and Italy, and received the backing of Paul Auster, who called Catelli’s argument compelling.

“A horrible conclusion, but after digesting the evidence Catelli has given us, it becomes difficult not to agree with him. Thus ‘car accident’ should now be filed in another drawer as ‘political assassination’ – and thus Albert Camus was silenced when he was 46 years old,” writes Auster in a foreword.

“I hope that the academics will not follow the old opinion that it was a simple accident,” said Catelli, who is talking to British publishers about an English translation. “I think we owe it to the memory of Albert Camus.”

Cambridge French literature professor Alison Finch was not persuaded. “Supporters of the assassination theory include a creative writer and film director (Paul Auster); a Czech writer and translator whose family were persecuted by the communist regime and who had good reason to hate communism (Jan Zábrana); the highly controversial lawyer Jacques Vergès, who, to be sure, defended Algerian independence fighters tortured by the French but who became infamous for defending the indefensible. Of course, this is what the law must do, but in general he’d be regarded as a maverick rather than a reliable commentator.”

Finch also questioned suggestions of French connivance. “This would mean that the assassination was approved at the highest level and presumably by De Gaulle. This, to me, is implausible. De Gaulle, an accomplished writer himself, had great respect for French intellectuals, including those whose views he disagreed with,” she said.

The Death of Camus draws to a close with Catelli expressing the hope that it will bring forth more evidence, “before the waves of time come to lay waste to the sandy, frail traces of what happened”.

• This article was amended on 10 December to remove a reference to Dmitri Shepilov having been the Soviet Union’s “minister of internal affairs”.