Prince William and Kate Middleton
Prince William, pictured here with Kate Middleton at the Earthshot Prize in 2021, was accused of having an affair with Rose Hanbury while his wife was pregnant with Prince Louis in 2019. Max Mumby/Indigo/Getty Images Max Mumby/Indigo/Getty Images

Royal author Omid Scobie claimed that Kensington Palace fed a British tabloid stories about Prince Harry and Meghan Markle in its desperation to quash rumours that Prince William had an affair with longtime friend Rose Hanbury while Kate Middleton was pregnant with Prince Louis.

In his new book "Endgame: Inside the Royal Family and the Monarchy's Fight for Survival," the biographer said that the palace's then-press secretary Christian Jones repeatedly tried to get The Sun, the first outlet to inquire about the rumours, to stop investigating the story.

He cited a former courtier who told him that "Christian was so desperate to stop (the rumor) and made it his mission to do so". Scobie claimed that Jones even told him that the entire ordeal was "stressing" him out and that he had to eventually promise a journalist from The Sun other royal-related scoops "in exchange for standing down on the rumours".

Scobie wrote that by June 2019, The Sun "suddenly pulled reporters off the hunt" and that a high-level courtier told him that "Christian helped make it end". He claimed that the tabloid instead shifted its focus to writing "a series of revealing stories" about Prince Harry and Meghan Markle."

Kensington Palace did not address the rumours about Prince William's alleged affair, but lawyers with London firm Harbottle and Lewis, which has represented the royal family before, sent a letter to one publication in April 2019 threatening legal action.

"In addition to being false and highly damaging, the publication of false speculation in respect of our clients' private life also constitutes a breach of his privacy pursuant to Article 8 of the European Convention to Human Rights," read the letter obtained by The Daily Beast.

To this day, Prince William and Kate Middleton have remained mum on the cheating allegations. Neither Scobie nor other news outlets confirmed the rumours. Hanbury, 39, the Marchioness of Cholmondeley, who is married to David Cholmondeley, 7th Marquess of Cholmondeley, was seen attending King Charles III's coronation on May 6, somewhat dispelling rumours that the claims have caused tension in her friendship with the royals.

Scobie admitted that he was being very careful when he included the cheating allegations in "Endgame". He told Entertainment Tonight that he does not believe there is any truth to the claims.

"I was very careful in the book to really focus on this, as the allegations against William, Kate's and their fallout with Rose Hanbury. For legal reasons, there are so many things that one can't go into," he said.

"But, I thought it was really important (to mention), even if a rumour is a rumour. And I really don't see proof that there is more to this than just a tittle-tattle, you know," he added. Scobie pointed out that the cheating claims will likely "never go away" because Prince William and Kate Middleton have "never addressed it" themselves.