Transcript for Princess Diana documentary faces backlash over secret tapes

third time. That battle over a new princess Diana documentary. It includes secret tapes never shown in Britain. Princess Diana's friends and family trying to block the broadcast. ABC's Deborah Roberts is here with the story. Good morning. Reporter: This film is causing quite an uproar because it reveals private conversations and 20 years after her death hounded by the Paparazzi, some are seeing it as yet another cruel betrayal of a vulnerable princess Diana. Just six days before the debut of the British channel 4 documentary "Diana" in her own words", friends of the late princess speaking out against its release saying the personal tapes in the film are a betrayal of Diana's privacy. The footage seen here in the trailer -- I was a prebl. Reporter: Include sessions Diana had with her voice coach Peter settelen in 1992. The recordings meant for Diana to watch and work on her public speaking are more like therapy sessions of her private thoughts. I should never have -- She went to the queen explaining all the trouble she had with her husband and the queen just shrugged her shoulders and basically said to get on with it. Reporter: When they were first undered her brother Charles Spencer claimed they belonged to the family. But after a long legal dispute they were returned to settelen in 2004. That same year excerpts were aired in the states but never shown in the uk. Settelen's attorney defending the release of the tapes on Monday to the bbc. Fact is that after Diana's death the claim to privacy actually failed because the police looked at them. The Spencer family looked at them presumably and so what was private to Diana was actually lost in the process. Reporter: The tapes putting a spotlight on the cracks in Diana's marriage to prince Charles. The princess even pointing to this moment from their engagement interview she called traumatizing. I'm amazed that she's being brave enough to take me on. And, of course, I suppose in love. Of course. Whatever love means. Brought up in a sense when you got engaged -- Reporter: Chapel 4 telling ABC news the subjects in the film 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. Of course, the question being did she want to tell that personal story? Prince William and Harry just released their own tribute to their mom in a documentary last week saying this would be the last time that they commented on their mother and, guys, kensington palace, no comment on the tapes. Again these are clips we have seen here in the U.S. But they had not seen there. So, it's nothing new. Everybody's seen it so once again you wonder why, why at this point. New developments in that father/durd murder trial.

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