Unheard audio tapes of Princess Diana talking about King Charles III, as well as her “hatred” for her stepmother Raine Spencer, are to air in an upcoming documentary. The recordings were taped three decades ago for her biographer Andrew Morton, who went on to publish the book <i>Diana: Her True Story</i> in 1992. On Friday, a few extracts of unheard clips were shared through ABC News ahead of the release of the documentary <i>Diana: The Rest of Her Story</i>. It serves as a follow-up to the 2017 film <i>Diana: In Her Own Words</i>, both directed by Tom Jennings. Speaking about her relationship with King Charles, who was then the Prince of Wales, she says: “He was so grown-up and here was Diana, a kindergarten teacher. I mean the whole thing was ridiculous.” Diana also spoke about her husband’s relationship with her family, revealing “he won’t even talk to mummy”. She continued: “Because at Harry’s christening, Charles went up to mummy and said: ‘We were so disappointed, we thought it would be a girl.’ And mummy snapped his head off and said: ‘You should realise how lucky you are to have a child that’s normal.' And ever since that day, a shutter’s come down, and that’s what he does when he gets somebody answering back at him, so to speak.” The clips were released a day after the 26th anniversary of Diana’s death on August 31, 1997, following a car crash in Paris, and a week before the first anniversary of the death of Queen Elizabeth II. The clips also reveal Diana’s feelings towards her stepmother, who married her father John Spencer in 1976. Speaking of their strained relationship, Diana says: “I was so angry. And I said: 'I hate you so much. If only you knew how much we all hated you for what you’ve done. You ruined the house. You spent daddy’s money.' “I have said everything I possibly could and Raine said: 'You have no idea how much pain your mother put your father through.' “I said: 'Pain, Raine? It’s one word you don’t even know how to relate to. In my job and in my role, I see people suffer like you’ve never seen. And you call that pain? You’ve got a lot to learn.' “I remember really going for her gullet.” The clips were released two days after the Duke of Sussex’s Netflix docuseries <i>Heart of Invictus </i>was released, where Prince Harry recalls the triggering return from his final tour of Afghanistan, which related to the trauma of losing his mother Diana.