AceShowbiz - Cher's son Chaz Bono is set to tell the world about his sex-change in a new documentary film. Bono, whose father is the late Sonny Bono, was born Chastity, but began gender reassignment in 2008 and this year applied to be legally recognised as a man after successfully completing the transformation.

The 41 year old has been documenting the process on camera and the footage has been made into a new film which is set to premiere at next year's Sundance Film Festival in Utah. Bono insists the currently untitled project will show "more than anybody's ever seen before" and he hopes it will fully explain the process.

He tells Entertainment Tonight, "I hope it's going to help change hearts and minds on this issue so that people can fully understand." Bono will also chronicle his story in a new book called "Coming Clean" which is set for release in 2011.