Even though he left Australia in 1980, Cave says that Wangaratta - his hometown in the southeastern state of Victoria, whose population now stands at 17,000 - still "inspired pretty much everything" in his artistic vision.

"It definitely had a huge impact on the kind of environments in my songs," Cave said.

"The idea of a river and open space and a small town... this invariably comes from living in that horrible town.

"It was a difficult place to grow up, there, because it had a very robust police force and they kind of made everyone's life f---ing misery," Cave said.

He made the comments at the US debut of a film about him, 20,000 Days on Earth.

Cave moved from Melbourne to London with his punk band The Birthday Party, whose bleak sound presaged the goth movement. The gigs were notoriously rowdy, with the film showing one crowd member urinating on bassist Tracy Pew.

Cave, speaking to a sold-out theatre off New York's Times Square, said his Australian origins hurt his initial reception in London and that he found freedom to develop as an artist when the band moved to West Berlin.

The British press "didn't understand at the time, way back then, that an Australian band could play music that was even remotely original. They figured that we spent a lot of time with the indigenous population," he said.

Cave eventually grew more experimental and incorporated elements of American blues into the dark landscapes of his follow-up act, Nick Cave and The Bad Seeds.

The band's most identifiable song, The Mercy Seat, tells a tale rich with Biblical references of a convict facing the electric chair.

Despite the religious overtones of much of his work, Cave said in the film that he had a "weird relationship with the idea of God."

"Within my songwriting, well, some kind of being like that exists. Someone's taking score, let's say," he is shown telling a therapist.

"In the real world, I don't believe in such a thing. When I had a real interest in religion was when I was taking a lot of drugs."

The film defies narrative styles, starting by showing Cave on a seemingly banal 20,000th day of his life - when he was between 54 and 55 years old. (He turned 57 on Monday.)

Cave is seen driving his Jaguar through Brighton, England, where he now lives with his wife, model Susie Bick.

He speaks, as if a taxi driver, to backseat passenger Kylie Minogue - a fellow Australian with whom he recorded the hit Where The Wild Roses Grow - and she appreciates Cave's fear of being forgotten.

The film - which premiered at the Sundance and Berlin festivals - shows Cave sharing pizza with his twin sons while watching a violent movie and lunching over eel with longtime collaborator Warren Ellis.

In the film, Ellis conducts French schoolchildren as they sing the operatic title track of the band's latest album, Push The Sky Away.

Cave - whose second novel, The Death of Bunny Munro and many songs are dripping with sex - dryly tells his therapist about his first sexual experience and how his father read to him from Vladimir Nabokov's Lolita.

He describes meeting Bick as the culmination of his life's "never-ending drip-feed of erotic data."

Iain Forsyth, the film's co-director with Jane Pollard, said they deliberately sought to avoid music documentaries' frequent "obsession with trying to strip away the man to reveal the real character - the real 'man behind the rock star.'"

"The mythology is as much a part of the story as anything else. In fact, it is the story," Forsyth said.