The Duchess of Sussex has been accused of implying that there was a suggestion her son Archie could not be a prince because of the possible colour of his skin.
Royal biographer Hugo Vickers also said Meghan Markle had misleadingly claimed in her interview that there was a discussion about whether the boy could take the title.
The 69-year-old expert insisted that there 'can have been no such discussion' about the matter because the rules on who can become a prince are 'absolutely clear cut.'
Mr Vickers spoke out after Meghan described her concern for Archie during her interview with Oprah Winfrey, first shown on CBS in the US on Sunday evening.
She also accused an unnamed member of the Royal Family of racism, claiming Prince Harry was asked by a close relative 'how dark' their unborn baby would be.
Mr Vickers told BBC Two's Newsnight last night: 'I think one of the problems with Prince Harry is that when he was a very little boy, he saw his mother (Diana) - and I understand this - as a victim, and he was too small and too young to protect her.
Prince Harry and his wife Meghan hold Archie in Cape Town while visiting in September 2019
'So of course when Meghan Markle said that she was a victim, he immediately leapt to her defence. I'm not quite sure that she was a victim in the same sort of way.
'And can I just take this opportunity to clear up one really serious thing that she said which was actually very misleading.
Why Archie didn't have a birthright to be a prince but could become one in future
Archie did not have a birthright to be a prince, but could potentially become one when Charles accedes to the throne.
That William and Kate's children have the HRH title and are styled as prince and princesses - and Archie is not - stems from a ruling more than 100 years ago.
In 1917, King George V issued a written order that only royal offspring who are in the direct line of succession could be made a prince and receive HRH titles.
The Letters Patent read: '...the grandchildren of the sons of any such sovereign in the direct male line (save only the eldest living son of the eldest son of the Prince of Wales) shall have and enjoy in all occasions the style and title enjoyed by the children of dukes of these our realms.'
Under the rules, only Prince William and the Duchess of Cambridge's eldest son Prince George - as a great-grandson of the monarch down the direct line of succession to the throne - was originally entitled to be a prince.
The Queen stepped in ahead of George's birth in 2013 to issue a Letters Patent to ensure all George's siblings - as the children of future monarch William - would have fitting titles, meaning they were extended to Charles and Louis.
Under the George V rules, Archie would be entitled to be an HRH or a prince when his grandfather Charles, the Prince of Wales, accedes to the throne.
'She said there was a discussion about whether Archie would be a prince or not. There can have been no such discussion.
'I could bore you to death on exactly who is a prince and who isn't, but it's absolutely clear cut. And that is how she led into that whole issue (about racism).
'She was almost saying... slight implication that he couldn't be a prince because of the possible colour of his skin, which is a bit naughty I think.'
During the interview Meghan insisted she held no attachment to the 'grandeur' of official titles until she discovered it meant Archie would not get his own security detail unless he was a prince.
Meghan said: 'We knew I was pregnant. We now know it's Archie, and it was a boy. We didn't know any of that at the time. We can just talk about it as Archie now. And that was when they were saying they didn't want him to be a prince or a princess - not knowing what the gender would be, which would be different from protocol - and that he wasn't going to receive security.'
Asked by Oprah how this worked, Meghan added: 'It's like, 'No, no, no, look - because if he's not going to be a prince,' it's like, okay, well, he needs to be safe, so we're not saying 'Don't make him a prince or a princess'-- whatever it's going to be.
'But if you're saying the title is what's going to affect their protection, we haven't created this monster machine around us in terms of clickbait and tabloid fodder. You've allowed that to happen, which means our son needs to be safe.'
Oprah also asked her: 'Was him being called a prince, Archie, being called a prince, was that important to you?'
She replied: 'If it meant he was going to be safe, then, of course. All the grandeur surrounding this stuff is an attachment that I don't personally have, right?
'I've been a waitress, an actress, a princess, a duchess. I've always just still been Meghan, right? So, for me, I'm clear on who I am, independent of all that stuff.
'And the most important title I will ever have is 'Mom.' I know that. But the idea of our son not being safe, and also the idea of the first member of colour in this family not being titled in the same way that other grandchildren would be.'
The Duchess also said: 'And so, I think even with that convention I'm talking about, while I was pregnant, they said they want to change the convention for Archie.'
The Duke and Duchess of Sussex's interview with Oprah Winfrey was first shown on CBS
Oprah said she had heard that it was Meghan and Harry who did not want Archie to have a prince title, but the Duchess said this was not true and it's 'not our decision to make'.
Oprah also said: 'You certainly must have had some conversations with Harry about it and have your own suspicions as to why they didn't want to make Archie a prince.
Meghan sighed and said: 'In those months when I was pregnant, all around this same time.... so we have in tandem the conversation of 'He won't be given security, he's not going to be given a title,' and also concerns and conversations about how dark his skin might be when he's born.'
The claims over the comment by the unnamed royal about skin colour were among the most astonishing allegations made during the interview.
The Duke and Duchess of Sussex introduce their son Archie at Windsor Castle in May 2019
And royal author Penny Junor told the Sun: 'It is hugely damaging for the Royal Family, for Britain and for everybody, especially by not naming anyone.'
But the Duchess's claims that Archie wasn't going to receive security were met with bafflement by palace insiders yesterday.
One described the logic as 'ridiculous', saying it had always been made very clear that as long as Harry was a member of the royals, his wife and children would be covered by the royal protection squad.
It is understood a great effort was made to get Meghan a female personal protection officer after she noted both Camilla and Kate had one, although eventually the woman officer only remained in post for about six months.