The brother of Diana, Princess of Wales, has claimed he was misled about William and Harry’s wish to walk behind their mother’s coffin.

Earl Spencer said that he expressed concerns with royal authorities before being informed that her sons wanted to do it, but subsequently realized that this was not the case.

Earl Spencer told Radio 4’s Today programme: “I was lied to and told that they wanted to do it, which of course they didn’t, but I didn’t realise that. It was the worst part of the day by a considerable margin, walking behind my sister’s body with two boys who were obviously massively grieving their mother.

“It was a sort of bizarre circumstance where we were told you just have to look straight ahead. But the feeling, the sort of absolute crashing tidal wave of grief coming at you as you went down this sort of tunnel of deep emotion, it was really harrowing actually and I still have nightmares about it now.”

“So there was the inner turmoil of thinking, ‘My God this is ghastly’, but then the point of thinking these two boys are doing this and it must be a million times worse for them.

“It was truly horrifying, actually.

“We would walk a hundred yards and hear people sobbing and then walk round a corner and somebody wailing and shouting out messages of love to Diana or William and Harry, and it was a very, very tricky time.”

He made the remarks as the 20th anniversary of her death approaches on August 31.

When their mother died in a vehicle accident in Paris on August 31, 1997, William, now the Duke of Cambridge, was 15 and Prince Harry was 12.

Following her death, which shocked the public, there was a massive outpouring of sorrow.

Earl Spencer, Diana’s younger brother, said that the Princes’ walking was a “bizarre and cruel thing” and that the funeral procession was “the most horrifying half an hour of my life.” Prince Harry, 32, has already talked about that fateful day, stating that no child “should be asked to do that.”

The earl also said that there had been four attempted break-ins at the family property where Princess Diana was buried after her death in a car accident in Paris.

He pledged to look after William and Harry, and his reference to the Spencers as Diana’s “blood family” was regarded as extremely hurtful to the Windsors.

Earl Spencer paid homage to his sister in a very personal address in Westminster Abbey in 1997, highlighting her problems with the media and the Royal Family.

Earl Spencer reminisced on his eulogy, which he delivered to his sister’s corpse a few days before she was buried at their family home, Althorp estate, in a radio interview recorded ahead of Diana’s 20th death anniversary. Earl Spencer defended his remarks, claiming that he was not “looking to make any jabs at anyone” including the royal family. “I don’t feel I said many pointed things,” he said. “I believe that every word I said was true and it was important for me to be honest. I was trying to celebrate Diana and if by doing that it showed up particularly the press I think in a bad way, well, they had that coming.”

The earl said that he reread his speech for the first time in 20 years and found it to be “very balanced”

Spencer said that he thought the Queen believed he had “every right to say whatever he felt,” and he remembered keeping the speech private so that no one else could have a voice in it.