A documentary which broadcast never-before-seen footage of Princess Diana has divided viewers in Britain. The 90-minute film, titled Diana: In Her Own words, showed video diaries of the Princess of Wales recorded at Kensington Palace in the early 1990s. Broadcaster Channel 4 aired the programme on Sunday night, three weeks before the 20th anniversary of her death. The tapes, which show Diana speaking about personal details of her marriage to Prince Charles, were made by her voice coach Peter Settelen. The decision to air the recordings was a controversial one, attracting criticism from Diana's sons, Prince William and Prince Harry, her brother Earl Spencer, and members of the British public. "Morally, this video being broadcast is so so wrong," Francine Gilmore wrote on Twitter. She was desperately unhappy #dianainherownwords." While viewer Louise Fillingham added: “Sensationalist. Over dramatic. Unsympathetic to anyone. Including Diana. Trash.” The tapes featured Diana discussing intimate details about her sex life with Charles as well as his affair with Camilla Parker Bowles. One viewer with the Twitter name The Way Photographic commented: "The years of PR Charles has put in to recover his image over all these years gone in one night #dianainherownwords." Others defended Channel 4 for airing the footage, with one user named Jason tweeting: "Good on @Channel4 for airing that #dianainherownwords." Another named Laura Mc Namee agreed, commenting: "I don't see why people were complaining about #DianaInHerOwnWords. It's nothing we didn't already know." Ahead of the documentary's airing, Channel 4 refused to back down in the face of criticism, claiming the excerpts are “an important historical source”. In a statement, it added: "We carefully considered all the material used in the documentary and, though the recordings were made in private, the subjects covered are a matter of public record and provide a unique insight into the preparations Diana undertook to gain a public voice and tell her own personal story, which culminated in her later interview for Panorama.<br/> <br/> "This unique portrait of Diana gives her a voice and places it front and centre at a time when the nation will be reflecting on her life and death."