Gigi Gaston, director of `The Cream will Rise', had never made a documentary film. She had barely heard any of the music of the gay icon Sophie B Hawkins, and she certainly had no idea that her probing would prompt such startlingly personal revelations from the pop star.

The two had been introduced in a restaurant by a mutual friend. Hawkins had invited Gaston to a rehearsal session and afterwards the screenwriter was compelled to say how much she would like to make a documentary about her.

"I was fascinated by the way Sophie directed her band, like directors direct their actors," says Gaston, 30. "I thought it might make an interesting rockumentary. And Sophie just said `Fine'. Next thing I was driving home and thinking, `What have I just done? I've never even picked up a camera before'."

Gaston understandably got cold feet, and a few weeks later decided to make her excuses.

"But Sophie got into my car and said, `You know what? After moving from New York to LA, all I've got to say about people in LA is, they're always saying they'll do something and they never do it. It's amazing how you say you'll do a documentary and, look, we start shooting tomorrow. Now what was it you wanted to tell me?' I just said nothing."

Gaston who had just sold a film script to Miramax, invested her own money in the film. "I had no expectation whatsoever of what the film turned into," she say. "All I knew, she was an interesting woman with a different perspective - different from my own.

"It began with Sophie reminiscing about her childhood and asking certain questions of her mother, and it just skyrocketed. In the movie Sophie says, `This documentary has lifted the lid off a coffin, and now I'm looking at stuff that I didn't know was there'. I asked, `Do you want to stop?' And she said, `No, how can I?' I think that during most of Sophie's childhood she wasn't paid much attention by certain parents," says Gaston, "and was left unprotected."

She insists that Hawkins had total control, and the final say over what went into the movie. "The point of the documentary, I hope, is to show how someone can overcome the limitations that our families can put on us.

"Let's say a child is being abused, day in, day out, and they see Sophie being called a whore by her mother, which Sophie's mother does on screen, and they can see that Sophie is not a whore, and that those words don't have to stop her ... I hope they will be able to see that cream always rises."

Gay and Lesbian Film Festival, National Film Theatre, to 26 March