Prince Harry and Prince William have been arguing for 'past year and a half', ITN's Tom Bradby has claimed.
Journalist Bradby - who was once friends with both princes - also denied negotiating ITV's rights for Harry and Meghan's incendiary interview with Oprah Winfrey.
During the bombshell tell-all, the Sussexes lobbed a number of grenade-like allegations at the monarchy, including claims a senior royal had made racist comments about their future child's skin colour.
Bradby claimed in an interview with The Times that reporting on the royals 'used to be quite a straightforward thing' when Harry and William 'weren't arguing and life was simple'.
But the brothers' relationship 'slowly descended into something that was difficult - personally and publicly - really over the past year and a half'.
Prince Harry and Prince William have been arguing for 'past year and a half', ITN's Tom Bradby (pictured) has claimed
Bradby was host of an ITV documentary filmed in South Africa in 2019 when Meghan, in a swipe at her new family, moaned: 'Not many people have asked if I'm okay. It's a very real thing to go through behind the scenes…it has really been a struggle' (pictured)
MailOnline's Dan Wootton was the first to reveal that Prince William ended his long-standing friendship with Bradby because of his concerns he sided with Prince Harry and sister-in-law Meghan in the increasingly bitter transatlantic war of the Windsors.
Bradby refused to be pressed on his current relationship with William, who was once so close to the journalist he was chosen to conduct the November 2010 engagement exclusive interview with him and Kate.
Bradby was host of an ITV documentary filmed in South Africa in 2019 when Meghan, in a swipe at her new family, moaned: 'Not many people have asked if I'm okay. It's a very real thing to go through behind the scenes…it has really been a struggle.'
Harry also used Bradby's documentary to publicly confirm a feud with his brother, admitting that he and William were 'on different paths at the moment'.
Addressing the documentary in his interview with The Times, Bradby said it was his own mental health struggle that helped him notice that the Sussexes were struggling.
He had to take lengthy time off from hosting News at Ten in 2018 after suffering what he previously called a 'mental health equivalent of a heart attack'.
Harry also used Bradby's documentary (pictured with Bradby) to publicly confirm a feud with his brother, admitting that he and William were 'on different paths at the moment'
Bradby said: '[I] was clearly influenced by my own experience and I didn't think they were in great shape, and so I altered the way I was planning to do the documentary.'
He said he 'felt like there was an untold story' behind Meghan's public face, so he asked her the question: 'Are you OK?'.
When pressed on whether the South Africa documentary, and the insight into the royal rift that followed, increased his stress, Bradby said: 'Well, it used to be quite a straightforward thing, right, because they weren't arguing and life was simple.
'And then it just slowly descended into something that was difficult - personally and publicly - really over the past year and a half.'
Also in the interview, Bradby recalled a lunch he had with Boris Johnson, prior to the now-Prime Minister revealing he would back Leave in the 2016 referendum.
Mr Johnson laid out the benefits of leaving and remaining on a napkin, Bradby said, before declaring he's not sure and its a 'difficult decision'.
Bradby said: When I got up, I tried to take the tablecloth with me and [press secretary] Will Walden was like, "No way." And he took the tablecloth, folded it, put it in his pocket. I assume he's still got it.
'But I left that restaurant convinced Boris was for Remain.'
It was last month revealed that the Duke of Cambridge has been left annoyed that the high-profile presenter sided with his brother Prince Harry.
Journalist Bradby - who was once friends with both princes - also denied negotiating ITV's rights for Harry and Meghan's incendiary interview with Oprah Winfrey (pictured)
While phone calls and communication between the Duke of Sussex in California and Bradby in London have become commonplace, William, in contrast, is said to no longer trust the high profile journalist who was once a close confidante.
A royal insider revealed: 'The friendship between William and Tom is very much over. The Duke feels let down by Bradby and the way he's acted over the past few months.
'William is a sensitive soul and believes it's in times of crisis when you find out who your true friends are. It would be fair to say Bradby hasn't been one of them.'
Our royal source added: 'The Duke will, of course, remain cordial and professional in his relations with senior media figures, but that special relationship he once had with Bradby is no more. William no longer sees him as a friend.'
Among senior royal aides, there is growing anger at the way Bradby and ITV News seem to have become a mouthpiece for Harry and Meghan's gripes about the Royal Family.
The royal source said: 'Some staff at the Palaces are even angrier about Bradby and the tone of his reporting at ITV News, which they consider to be pro-Harry and Meghan.
'It's well-known Bradby personally communicates with Harry on a regular basis and that is pretty obvious to royal aides who know how things work.
'But it's been very difficult to accept given the long history between Bradby and William.'
William was once so close with Bradby that he was chosen to conduct the Cambridges' engagement interview.
Bradby went on to attend the nuptials at Westminster Abbey as a guest.
A spokesman for William at the time said: 'The couple asked to record this interview specifically with Mr Bradby, whom they have both known for some time.'
Bradby refused to be pressed on his current relationship with William, who was once so close to the journalist he was chosen to conduct the November 2010 engagement exclusive interview with him and Kate (pictured)
But Bradby was equally close with Harry, attending his Windsor wedding to Meghan, alongside other media figures including Oprah and James Corden.
The friendship with both brothers was solidified during Bradby's time as ITV's royal correspondent.
He travelled with Harry to Lesotho in Africa to make a 2004 documentary.
Bradby's closeness to the brothers then exploded into the public domain as part of the News of the World phone hacking scandal, when details of a call between him and a royal staff member was published in the Sunday newspaper.
Like Harry, Bradby has been publicly open about his mental health issues, revealing he had to take lengthy time off from hosting News at Ten in 2018 after suffering the 'mental health equivalent of a heart attack'.
The Mail on Sunday revealed last month that Bradby has 'significant sway' over how Meghan is portrayed more widely on ITV.
They reported he may have been involved in pointing the Duchess 'in the right direction' over how to complain about Piers Morgan's criticism of her on Good Morning Britain, which resulted in him quitting the show.
A source told the newspaper: 'Tom Bradby has a certain caché at ITV as their news man. He is also the man with the golden goose in the bosses' eyes as he has a hotline to Prince Harry.'
Kensington Palace declined to comment to reports about Bradby's fall out with Prince William, first published by MailOnline.
A spokeswoman for ITV News said: 'Unfortunately at this moment we won't be in a position to comment.'