Transcript for New documentary shows footage recorded by Princess Diana's vocal coach

tonight to the new controversy over video tapes of princess Diana, recorded by her voice coach, and about to be seen across the uk. Here's ABC's Deborah Roberts. Reporter: They are deeply personal, explosive moments with a vulnerable princess moments some of Diana's friends say the public has no right to see. I knew that something profound was coming my way. Reporter: Recordings made in 1992 during sessions with Diana's voice coach, Peter settelen. If you feel strong about a point, make it. Strongly. Reporter: Meant for her to practice public speaking, the clips seen in this new documentary comes from footage likely never thought would air publicly. Revealing intimate detail of her troubled marriage. We met 13 times and then we married. Reporter: How the queen refused to help when she confided in her. Even reliving this cringe inducing moment from her engagement announcement to prince Charles. I'm amazed that she's been brave enough to take me on. And I suppose in love? Of course. And whatever "In love" means. Yes. Reporter: Calling it traumatizing, Diana longing for love. I was brought up in a sense that when you got engaged to someone you loved them. Reporter: After years of legal disputes with Diana's family, settelen is now free to release the tapes. They're being aired just as princes William and Harry try to remember their mother in a different way in a separate documentary released just last week. All I can hear is her laugh in my head, it was that love that -- that even if she was on the other side of a room that you, as a son, you could feel it. And Deborah Roberts is here with us now. Both prince William and prince Harry were candid, and neither of them are talking about this documentary that would come out? They made it clear that was the last time they would speak publicly about their mother's death. This is airing this Sunday in Grabbe. They are calling this a historical source. Should Diana's private moments remain private or do they belong to the public? Deborah, thank you. We turn to the economy and

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