When indigenous Australian teenagers Rowan McNamara and Marissa Gibson arrived in Sydney from the Outback last week, they grinned widely at seeing their faces staring out from movie posters adorning 150 bus shelters around the city.

This week they will get an even bigger surprise when the 15-year-olds, who live on remote Aboriginal communities in the Northern Territory, arrive on the French Riviera as the stars of Australia's shining hope for the Cannes Film Festival.

The pair star in Samson and Delilah, the debut feature from indigenous director Warwick Thornton. The film has achieved critical acclaim in Australia since opening to sold-out cinemas last weekend, and has been officially selected for this Saturday's coveted opening weekend slot as part of the Un Certain Regard category at Cannes.

It is a beautiful, if brutal, portrayal of teenage love in the Outback, and forms a moving snapshot of the harsh everyday realities – including petrol sniffing, violence and destitution - faced by the those living in the hundreds of small, remote Aboriginal communities which surround Alice Springs.

Thornton, an Aboriginal who grew up in Alice Springs, arrives in Cannes later this week with Rowan, Marissa and his producing partner Kath Shelper. The writer, director and cinematographer said the recognition of being screened at the prestigious film festival "validates" his movie.

"You make these films for your mob and yourself in a sense, especially the sort of harder, reality-based films," Thornton told The Times.

"It's really important for me to show these films to my people, because they bring up the issues they are all dealing with, and it's really important for them to start taking steps in the right direction.

“But it’s also really good for our original Australian stories - not only indigenous stories but other Australian stories, which tell who we are and how we work – to be shown to a wider audience.”

Samson and Delilah was filmed on an abandoned community mission in Alice Springs for a minimal budget of $AU1.2million (£600,000), with a small cast and crew – Marissa’s real grandmother played her nanna in the film, and Thornton's brother played a homeless man living under a bridge who befriends the teenagers.

Thornton – who also wrote the script and was the film’s cinematographer - describes it as a "really beautiful, hard love story". Stunningly shot with a hand-held camera in the Australian Outback, the two teenagers barely speak throughout their courtship.

One of Australia’s most respected film critics, David Stratton, described Samson and Delilah as “quite simply, one of the finest films ever made in this country”.

“It a triumph for all concerned,” he said. “This movie may well be heralded as something close to a masterpiece.”

Thornton is not the only one receiving accolades - both Rowan and Marissa, first-time actors who were plucked from their local communities to star in the film, have received auditions for other movies since its release.

Like the Stolen Generation drama Rabbit Proof Fence and Aboriginal-language Dreamtime film Ten Canoes (which won the Un Certain Regard special jury prize at Cannes in 2006), there is hope in Australia that Samson and Delilah will be well received internationally.

Thornton said he is working on more script ideas, including a period piece and a romcom, all with indigenous themes. "I'm an Aboriginal person, it is something that is the fire that burns inside me, so that’s why I make films like this," he said.

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