Prince William reveals how Princess Diana once embarrassed him

Prince William and Harry have revealed some of the fond memories they have of their late mother, Princess Diana, who died in a car crash in Paris in August 1997.

William, in a new documentary titled Diana, Our Mother: Her Life and Legacy, has disclosed how his mother once embarrassed him by making her guests - Naomi Campbell, Christy Turlington and Cindy Crawford – stand outside his room as he returned from school, knowing well he was a huge fan of the trio.

"There's a couple of memories I have that are particularly funny," the 35-year-old royal said, according to The Sun.

"Just outside this room where we are now, she organised, when I came home from school to have Cindy Crawford, Christy Turlington and Naomi Campbell waiting at the top of the stairs."

"I was probably 12 or 13 year old boy who had posters of them on his wall and I went bright red and didn't quite know what to say and sort of fumbled, and I think I pretty much fell down the stairs on the way up."

"I was completely and utterly sort of awestruck. But that was a very funny memory that – that's lived with me forever about her loving ... and embarrassing and sort of, you know being – being the sort of the joker."

Prince William's younger brother Harry,32, shared his elder brother's sentiment and said their mother "was one of the naughtiest parents", who told him that he could be as naughty as he wanted but must never get caught.

"Our mother was a total kid through and through," Harry said. "When everybody says to me, you know, so she was fun, give us an example...all I can hear is her laugh in my head. And that... sort of crazy laugh of where there was just pure happiness shown on her face."

Harry also admitted that it has taken them a long time to speak about their mother.

"Arguably, probably a little bit too raw up until this point. It's still raw," he said.

"There's not many days that go by that I don't think of her," William added. "Her 20th anniversary year feels like a good time to ... remember, you know all the good things about her and hopefully provide maybe a different side to her that others haven't seen before."

Diana, Our Mother: Her Life and Legacy airs on ITV at 9pm on 24 July.