Every year at The Times BFI London Film Festival, there is at least one discovery, a film that stuns audiences and dominates the debates in the bars of the BFI Southbank. A movie that, in its own way, is a landmark in film-making. This year that film will be Samson & Delilah. A brutally beautiful debut feature from the Australian writer and director Warwick Thornton, Samson & Delilah tells a love story about two Aboriginal teenagers living in a tin shack wasteland full of discarded souls. A tragedy flings them onto the streets of the nearest city, Alice Springs, and into a downward spiral of petrol-sniffing oblivion. There is a bleak poetry to this tentative romance in the Aussie badlands and — crucially — there is hope and joy enough to balance out the savage honesty.

Though it has yet to fully register on the mainstream radar, Samson & Delilah has not exactly come out of the blue. The film was screened in Cannes in May this year, where it won the Camera d’Or prize for best first feature. The jury described it as “the best love film we have seen for many a year”. It has earned ecstatic reviews in its native Australia (“One of the most wonderful films this country has produced”) and is the highest-grossing Australian production of the year. And it was recently announced that Samson & Delilah (which is shot predominantly in the aboriginal language Warlpiri) will be Australia’s entry in the Foreign Language Oscar race. Not that there is much of a language content — part of the potent magic of Samson & Delilah comes from the fact that the picture is almost entirely silent.

Although Thornton, who grew up in an indigenous community much like the one he depicts in the film, learnt about storytelling from the aboriginal oral tradition, he grasped the power of the visual image very early on. He might be new to feature film-making, but Thornton, 38, has been an acclaimed cinematographer and maker of short films for nearly 20 years.

“You don’t have to talk,” says Thornton, a physically imposing, burly presence with an affable, open manner. “When I was 14, I didn’t have that Disney, Hannah Montana dialogue with girls. I was incredibly embarrassed and ashamed. If you really liked a girl you wouldn’t talk to her. If you wanted her attention you would throw a rock at her. Cinema gets a bit cheap with dialogue. ‘I’m angry, I’m sad.’ They use the word. Why don’t you act it?”

There is no question that this is a very personal film for Thornton. It was made about and for “his mob”, as he describes the Aboriginal community, but Samson & Delilah’s broader appeal is down to its unflinching authenticity. Thornton wrote what he knew. “Cinema,” he says simply, “saved my life. Sampson & Delilah is my story. I wasn’t a petrol sniffer but I did grow up on the streets of Alice Springs as a kid. And I didn’t like school, it was much more fun getting chased by the police at two o’clock in the morning. I was incredibly lost and out of focus. I had friends who died on the streets.”

What saved Thornton was a job as a camera assistant on a documentary that fascinated him to such an extent that running wild on the streets no longer held such an appeal.

While he clearly identifies with both the kids in the film — the stringy, livewire “cheeky little rabbit” Samson (played by Rowan McNamara) and the serene, nurturing Delilah (Marissa Gibson, pictured with McNamara) — Thornton’s background differs in one crucial way. While the kids in the film are defined by neglect and absence of parenting, for Thornton, family is everything. “I grew up in a family of incredibly strong women struggling to keep focus and direction for the family and to put food on the table.”

Now Thornton has involved his own family in the film: his 16-year-old son has a small acting role, his daughter plays violin on the score and his wife, the film-maker Beck Cole, shot a documentary about the production. “You work with people you love,” Thornton says.

The biggest single contribution from a family member came from Thornton’s older brother Scott, who plays Gonzo, a down-and-out vagrant who offers kindness to the runaway kids. An alcoholic for most of his life, Scott Thornton is himself a “parky” who lives rough for most of the year. His brother cast him in the film on the condition that he went to rehab and dried out. It took Scott five attempts, but he eventually made it though rehab and into some of the film’s most powerful scenes.

Lyrical though it is, this is a tough little movie that pulls no punches in its indictment of white Australia’s treatment of its indigenous people and of the neglect within the aboriginal communities. But Thornton argues that the film has the power to change. “It’s a universal story. There are Samsons and Delilahs everywhere. That’s the gorgeous thing about cinema — I truly believe that if you watch the film, when you leave you’ll be a better person.”

Samson & Delilah, Vue7, Oct 24 (6.15pm), Oct 25 (3.45pm)

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