The Outback's Samson and Delilah

An Aboriginal love story starring two untrained actors has created a huge buzz ahead of the Cannes Film Festival

It is the film some critics are saying Baz Luhrmann ought to have made instead of his overblown Outback epic, Australia. Produced for a sum equivalent to Luhrmann's catering budget, Samson and Delilah, set in a remote Aboriginal settlement, is winning awards and creating an international buzz even before its cinema release.

Selected for next month's Cannes International Film Festival, Samson and Delilah is a brutally realistic depiction of daily life in the indigenous communities of central Australia. It stars two 14-year-old untrained actors, features minimal dialogue, and is being hailed as one of the most important films ever made Down Under.

Samson and Delilah are two teenagers growing up without family support in a community outside Alice Springs, in the Northern Territory. They fall in love. Faced with the challenges of poverty, violence, boredom, drugs and sexual abuse, they are almost crushed, but survive.

The story's backdrop is the hauntingly beautiful red desert landscape of the interior: a region unvisited by most Australians, who are more likely to pass by at 30,000 feet on their way to Europe or South-east Asia. Warwick Thornton, the film's writer and director, believes that while they're aware of the area's social problems, they view its Aboriginal inhabitants as barely more than statistics.

Thornton, an indigenous film-maker based in Alice Springs, aims to humanise his people through Samson and Delilah, which will be released nationally next week. He hopes to open the eyes of mainstream Australia to their plight, but insists his first feature-length work is about the redemptive power of love, not a political statement.

First shown in March at the Adelaide Film Festival, where it won the Audience Award, the movie – which cost just A$1.6m (£771,000) to make – had its Australian premiere 10 days ago in Alice Springs. More than 2,500 people, many from the Aboriginal camps that ring the town, attended an outdoor screening at the old Telegraph Station.

Around the nation, meanwhile, Samson and Delilah is receiving reviews that Luhrmann, whose A$180m film was widely panned, could only dream of. The Age in Melbourne described Thornton's film as "a film of delicate simplicity and gut-wrenching power", while another critic said it was "one of the bravest Australian films I've ever seen". Variety magazine called the movie "an engrossing and touching snapshot of an Australia too often left on the cutting-room floor".

It confronts the problems of black Australia with an unflinching honesty. Samson, feckless but endearing, is a petrol-sniffer who reaches for his tin can – representing oblivion – the moment he wakes up in his shack. He roams the rubbish-strewn community, making trouble, and is beaten up by his elder brother after smashing the latter's guitar.

Delilah, a quiet, serious girl, looks after her ailing grandmother, wheeling her to the clinic and to the tin-roofed church every day to pray. An unscrupulous art dealer buys an elaborate dot painting from the old woman for A$200, then offers it for sale for A$22,000 in his Alice Springs gallery. When her grandmother dies, Delilah is attacked by stick-wielding relatives accusing her of neglect.

She and Samson flee to Alice Springs, stealing a car, and descend into a spiral of misery, living rough under a bridge and pilfering food. The only person to show them kindness is an alcoholic tramp, Gonzo.

Thornton, 38, is familiar with this milieu. "I grew up in Alice Springs and I spent most of my childhood on the streets at night," he said in an interview in Sydney. "Everything in that film I have witnessed."

Poignantly, Gonzo is played by Thornton's elder brother, Scott, an itinerant alcoholic in real life. The director persuaded him to undergo rehabilitation before shooting went ahead last year.

The two young leads are also steeped in the environment, which is why Thornton cast them rather than experienced actors. Rowan McNamara grew up in Santa Theresa, outside Alice Springs and his elder sister sniffed glue for years. Marissa Gibson spent her childhood in the isolated outpost of Kintore, where petrol sniffings, beatings and stories of girls forcibly "taken out bush" were rife. The Northern Territory is dotted with such dysfunctional settlements, some worse than others, none without dire problems. They include Mutitjulu, situated in the shadow of Uluru, or Ayers Rock, one of Australia's biggest tourist attractions; most of its 400,000 annual visitors are not even aware of the community's existence. An inquest took place last week into the suicide of a 15-year-old Mutitjulu girl, allegedly given petrol by adult men in exchange for sex.

That a girl should live and die in such circumstances is difficult to comprehend, and, likewise, Samson and Delilah, while utterly compelling, makes for uncomfortable viewing – particularly since it reflects real life unembellished. Thornton says: "As far as telling a story that's realistic, I needed to go all the way and not hold back on how grim things are.

"I'm trying to say: 'There's a world in Australia that you haven't seen, and it's beautiful, it's hard, it's gut-wrenching, but it's empowering, and for you to see this side of us will make you a better you.'" Thornton, whose short films have won several awards, including one at last year's Berlin International Film Festival, is particularly exercised by the fate of young Aborigines with nothing to do. He admires their "beauty and strength", saying: "Most 14-year-olds in Alice Springs are walking around with the knowledge of a 90-year-old, from what they've experienced. They're bullet-proof."

Samson and Delilah survive, although the former's petrol-sniffing lands him in a wheelchair. Delilah looks after him tenderly. Their love – which blossoms after he scrawls "S4D onley [sic] ones" on the wall of a store, and she then tosses him a packet of beef jerky (dried sliced meat) – is largely wordless. In traditional Aboriginal society, body language and gestures count for more.

The film has little in common with the Bible story, which Thornton read only recently. He points out that many Aboriginal people have Biblical names, having grown up in Christian missions. And indigenous women cut their hair while in mourning. (Both Delilah and Samson do so, the latter not realising the custom does not apply to men.)

Some scenes have particular resonance. In an Alice Springs supermarket, the white check-out girl looks at Delilah's bruised, swollen face, takes her money and intones: "Have a nice day." In the pedestrian mall, Delilah sits down near two white schoolgirls her age; one is eating a big ice cream, the other talking excitedly on a mobile phone. To them, she is invisible.

Later, Delilah tries to sell paintings to stony-faced tourists drinking coffee in the mall. A waitress orders her to leave. She walks around a church in a daze, gazing at the statues of Jesus. The white priest watches her, but says nothing.

According to Thornton, his movie offers no answers, only questions. And he is lukewarm about the state's so-called intervention into failing black communities, noting that successive governments have been trying different solutions, without success, for decades. "The intervention will come and go, and these kids will still be in trouble," he observes.

As for Baz Luhrmann, Thornton is diplomatic, suggesting that their films have different aims. While Luhrmann's is a romanticised portrayal of Australia 70 years ago, he says, "if you want to tell the world what Australia is like today, you should watch Samson and Delilah".