In videos shot in the early 1990s, Diana's former voice coach Peter Steelen revealed that Prince Charles and Princess Diana had a lackluster sex life and it was all because of Charles' longtime mistress, Camilla Parker-Bowles.
Channel 4 in the United Kingdom has defended itself against accusations of exploitation and insensitivity over its decision to broadcast video recordings of Diana, Princess of Wales.
Defending its decision, Channel 4 said the footage was an important historical resource.
"We carefully considered all the material used. the subjects covered are a matter of public record".
The documentary features Diana speaking candidly and informally about her upbringing, her courtship with the Prince of Wales, her troubled marriage and her public life.
Several British media sources are reporting that Mr Spencer, Diana's younger brother, has asked the broadcaster not to air the documentary saying it would hurt her sons, Prince William and Prince Harry.
Dickie Arbiter, a former spokesman for the Queen, told Sky News that airing the tapes was "absolutely shameful" and it seemed there was "grubby blood money running around".
They were made during a tumultuous period in Diana's marriage to Prince Charles and reveal her distress about their relationship. "It will give viewers an insight into the process she went through as an innocent and inexperienced young woman, suddenly launched into this unusual world".
Meanwhile, Rosa Monckton, a confidante of Diana's is writing to the channel in a bid to stop the broadcast which is scheduled for Sunday 6 August.
"At the time, the general public overwhelmingly took her side, and whether or not you believe that she should have been so open is really for the viewers to form their own opinions".
Royal author Ingrid Seward told the paper she thought Diana's legacy was being "exploited".
The footage, captured at her private residence in Kensington Palace, shows Diana rehearsing her speaking voice and reflecting at length about her life.
She said: 'This doesn't belong in the public domain.
On being dated by Charles, Diana says: 'He chatted me up, you know, he was like a bad rash, he was all over me, and I thought, you know, urgh, you know?'
"Harry and I were in a desperate rush to say goodbye, you know, "See you later"... if I'd known now obviously what was going to happen I wouldn't have been so blase about it and everything else", Prince William said. "Charles is hopeless". And that was it, that was help", she adds.
On her attempt to confide in the Queen: "I went to the top lady and said: "I don't know what I should do".
"But now, coming up to the 20th anniversary, with everyone, including her own children, discussing Diana and revisiting her life, he wants Diana to be able to speak for herself".
She recalls the night that her relationship with the Prince of Wales turned romantic.