Charles Spencer, who has made it his mission to correct inaccuracies about her life, said it was his “duty to stand up for her when I can”. The Earl, who said he worried many people would think her depiction in the hit show was true, last night called for the fresh probe into the BBC’s Panorama interview with his sister to be allowed to “examine every aspect” around the controversial programme. Lord Dyson, a retired Supreme Court judge, has been appointed to lead the inquiry into claims BBC reporter Martin Bashir secured the interview using forged documents to convince Diana that her staff were betraying her and then covered it up. Earl Spencer wrote on Twitter: “As I’ve told the BBC this evening, I’m not at all satisfied with the parameters they’ve set around their enquiry into the BBC Panorama interview with Diana of 25 years ago tonight.
“Lord Dyson must be free to examine every aspect of this matter, from 1995 to today, as he sees fit.”
The thrice-married peer, 56, told of his reservations about The Crown in an interview with Alan Titchmarsh to be screened on ITV’s Love Your Weekend tomorrow morning.
He said: “The worry for me is that people see a programme like that and they forget that it is fiction.
“Americans tell me they have watched The Crown as if they have taken a history lesson. Well, they haven’t.
“It is very hard, there is a lot of conjecture and a lot of invention, isn’t there? You can hang it on fact but the bits in between are not fact.”
Of his loyalty to Diana, he said: “I feel it is my duty to stand up for her when I can. She left me for instance as guardian of her sons. And we grew up together – you know if you grow up with somebody they are still that person, it doesn’t matter what happens to them later.”
Other royal insiders have expressed concern that the series is peddling falsehoods and damaging the reputation of the monarchy.
The show’s creator, Peter Morgan, has admitted making up scenes and dialogue but has defended his right to use artistic licence.
Former Palace press secretary Dickie Arbiter, who has described the series as a hatchet job, said: “I think the characterisation of all the players is awful, save for Emma Corrin, who does a pretty good job of Diana – as good a job of Diana as Claire Foy did of the Queen in the first two series. But the rest of the characters are pretty awful.
“Peter Morgan has admitted it’s not history, it’s not a documentary; it’s drama.
“And he has taken absolute liberties with dramatic licence in what he has written.”
Royal historian and biographer Hugo Vickers complained the monarchy was wrongly portrayed as an institution that would crush anyone who stepped out of line to survive.
“You rather end up disliking the Royal Family,” he said, after watching the fourth series and taking issue with numerous factual errors. “You can’t help but feel he has an agenda to make the Queen look bad.”