ITV cut claims that Prince Wiliam and his staff planted stories about his brother’s mental health after being warned they were defamatory.
The documentary had originally planned to air allegations of leaking from the Duke of Cambridge about Prince Harry.
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Omid Scobie, the Duke and Duchess of Sussex’s biographer had suggested on the show that senior palace aides had briefed newspapers over concerns regarding Harry’s state of mind.
He claimed that it was following an interview with journalist Tom Bradby in 2019 where Harry said that he and his brother were on “different paths”.
However Kensington Palace are understood to have warned ITV that the suggestion, if aired, would be defamatory in that it was substantially untrue.
Mr Scobie explained that he believes that the interview about a rift between the brothers was given a negative spin by palace sources.
The claims were meant to air in the prime-time documentary “Harry and William: What Went Wrong?” this evening.
But the MailOnline have reported that they were cut from it at the 11th hour over defamation fears.
Kensington Palace are thought to have contacted the producers of the documentary in relation to a “number” of details.
These included a “clear rebuttal” of Mr Scobies suggestion that William was the one who expressed an opinion on his brother’s mental state.
The author had no evidence to support his claims, and after “carefully considering” the palace’s request ITV chose to remove any reference to mental health from the clip.
But they chose to keep in Mr Scobie’s comment about an alleged briefing from Kensington Palace relating to Harry.
He has been an outspoken defender of the Duchess of Sussex and he told the programme she came into the Royal family “driven and ready to work and that immediately ruffled feathers”.
During the 2019 interview Prince Harry admitted to Tom Bradbury that he did not see his brother as often as he once did, and he failed to deny a rift.
Harry hinted at the strained relationship in an ITV documentary about him and Meghan Markle during their ten-day tour of Africa with son Archie.
As part of the documentary, the author of Battle of Brothers, Robert Lacey, said that a source close to William claimed that he believed Meghan had always had an “agenda”.
In Mr Lacey’s book, he claimed that Prince William raged at Meghan’s “merciless” treatment of staff and called her “that bloody woman”.
In the book, he writes that conflict between Princess Diana’s “two bitterly divided sons does not seem likely to end any time soon”.
Lacey said that Prince William will have no choice “but to swallow his pride and smile” beside his sister-in-law Meghan on next year’s Platinum Jubilee balcony.