Boréal had publicly stood by Orélien just last week, but on Wednesday said that "new information, confirmed over the past few days, indicates that artificial intelligence was used in the writing process" of the novel, per France 24.

The publisher announced it was ending its professional relationship with the 38-year-old Haitian-Canadian writer, who fled Haiti after the 2010 earthquake and whose migration novel had been scheduled for translation in more than 20 countries.

The reversal came after allegations first surfaced in September, which Orélien had repeatedly denied.

According to both France 24 and Al Jazeera, Boréal said it gathered all working versions of the novel and hired an outside party to analyse the various drafts. The results obtained this week revealed traces of AI tags in the metadata of certain documents, the publisher said.

Boréal acknowledged it does not know the extent of AI's use in the writing process and that "we will likely never have a definitive answer."

The publisher also said it had initially tried to work with Orélien to gather evidence to prove his innocence, an effort that was inconclusive, after which Orélien announced he would not provide any further information.

France 24 reports the novel had already been withdrawn from the shortlist for France's top book prize, the Goncourt, after tests with the AI detector Pangram indicated a 100-percent probability it contained computer-generated text.

Al Jazeera likewise reports the Goncourt removed "C'était ça ou mourir" from its shortlist following the Pangram result. The book had been a top seller and was shrouded in suspicion before the publisher's own investigation, making its fall from prize contender to dropped author remarkably swift.

Orélien has called the allegations "slander and heresy" in a statement to AFP earlier this month, saying he began the book in late 2017 and completed a first draft of more than 300 pages in 2019, before AI services such as ChatGPT were widely available.

He acknowledged using tools for research, particularly foreign idioms, but insisted not a single sentence was created by a machine. Al Jazeera reports he told the French newspaper Libération on Wednesday that he had used AI "in the creative process" for "historical research."

When the allegations first surfaced in September, he said he suspected racism was behind the attacks on him.