Inside Heath's 'sleepless' nights

Heath Ledger's close friend Matt Amato has opened up about his decision to make a documentary about the late actor's life.

Admitting he's not sure if Heath would have wanted to be the subject of a film, Matt says the doco I Am Heath Ledger, which premieres at the Tribeca Film Festival next week, also shows the star's struggles with his own insecurities.

“It’s kind of a rule of thumb for me to self-doubt, to think I fooled them,” Heath is shown saying in on clip.

Co-director Derik Murray says the those close to Heath, who died at age 28, were worried about his inability to turn off him "manic energy" and get some rest.

“He’d sleep either zero or two hours a night for years. He would call people up in the middle of the night," Derik told NY Post.

While the documentary features interviews with former girlfriend Naomi Watts, friend and musician Ben Harper, directors Ang Lee and Catherine Hardwicke, and actors Djimon Hounsou, Ben Mendelsohn and Emile Hirsch, Heath ex Michelle Williams, whom he shared a daughter with, didn't participate.

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However Michelle's lack of participation doesn't mean she didn't give her blessing for the project.

“She said, ‘We should do something now. Matilda [their daughter] is curious,’" Matt tells the publication.

“My only reservation is that, is it as big and beautiful and full of spirit as Heath was? Of course not. But it carries a glimpse in it. And I think he would appreciate the love.”

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