Former Pope Benedict wants his name removed as co-author of a new book on the issue of priestly celibacy, his personal secretary said on Tuesday, in the latest twist to a saga that has kept the Roman Catholic world riveted.

Archbishop Georg Ganswein told Reuters that, at the former pope’s behest, he had asked the principal author of the book, Cardinal Robert Sarah, to contact the publishers to make the necessary changes.

The book, “From the Depths of Our Hearts”, is due to be published in France on Wednesday. Excerpts were released at the weekend, angering some Roman Catholic scholars, who said Benedict risked undermining his successor, Pope Francis.

The book’s American publisher, Ignatius Press, said in a statement that it still “considers this a co-authored publication”, indicating that it may not comply with the former pope’s requests when the English version is released next month.

The episode has underscored the polarisation between conservatives and progressives in the 1.3 billion-member Church and prompted fresh debate on the role of a former pontiff.

Hours earlier, Cardinal Sarah rejected media accusations that he had used Benedict’s name without authorisation and that he had taken advantage of the frail, 92-year-old former pontiff, who in 2013 became the first pope to resign in 700 years.

“I solemnly affirm that Benedict XVI knew that our project would take the form of a book. I can say that we exchanged several texts to establish the corrections,” Sarah, 74, wrote on Twitter.

He later said that because of the polemics, in future editions of the book, Benedict would be named as a contributor and not a co-author. “However, the full text remains absolutely unchanged,” he said.

In the book, Benedict and Sarah defend priestly celibacy in what some have seen as a strategically timed appeal to Francis not to change the rules after a proposal that he allow older married men to be ordained on a limited basis to deal with a shortage of priests in the Amazon. Francis is preparing a document on the issue..

Sarah also issued a long statement in his own defence, detailing his recent meetings with Benedict and restating that the former pope was informed of everything, including the cover of the book.

He said accusations that he was manipulating Benedict were “despicable” and that his allegiance to Francis was “total”. He also published a signed letter from Benedict, in which the former pope wrote in Italian: “For my part, the text can be published in the form you have foreseen.”

The episode has sparked heated debate, including on social media far from the Vatican, on the role Benedict should have, if any, and whether he is being used by others.

“Has the pope emeritus become a brand that some manipulate and administer at will?” Luis Badilla, head of the Catholic website Il Sismografo, said in an editorial.

“Can the status of the emeritus pope be left in the hands of private people who do not have to answer to anyone?” Badilla said in apparent reference to those with access to Benedict, who lives in seclusion in a former monastery in the Vatican.

It is not the first time that Benedict has spoken out on Church matters despite his public vow to live “hidden from the world” after his abdication in 2013.

Benedict caused a stir last year with an essay in which he blamed the Church’s sexual abuse scandal on the effects of the sexual revolution in the 1960s.

Many Catholic theologians and abuse experts rebuked him, saying he was trying to shift blame away from the Church.