tonight to the new controversy over video tapes of princess diana, recorded by her voice coach, and about to be seen across the uk. diana never knew these tapes would become public, and tonight her family and friends are arguing they shouldn't be. 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 diana likely never thought would air publicly. revealing intimate details 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.