The Mexican director of the Cannes prize-winner Silent Light tells Chiara Arroyo why he chose to make a film about an isolated German-speaking sect.

Just a decade ago, Mexico's Carlos Reygadas was a high-profile human-rights lawyer for the European Commission, specialising in armed conflicts. Now he is one of the world's most exciting film-making talents.

As aesthetically stunning and thematically challenging as any Reygadas film to date, his third film, Silent Light (Stellet Licht), is set in a Mennonite community in northern Mexico and shot in an obscure German dialect, the language of the Mennonites, a pacifist Christian sect. The film is a love story, a drama about a married man who violates the teaching of his religion by falling in love with another woman.

'I wanted to tell a universal story like a Hans Christian Andersen fairy tale,' Reygadas explains. 'The characters are archetypes. They suffer the emotional conflict between inward duty and the external obligation.'

Why a Mennonite story' 'Part of my family is from Chihuahua in northern Mexico,' he explains. 'My uncle has a range where some Mennonite people work. I used to hunt goose with my father and also Mennonite people came along. I'm fascinated by their aesthetics, their visual world. The women's hats for example. It's such a different culture. And I love the countryside.'

Last summer a crew of just 11 people moved to Chihuahua for the three-and-a-half month shoot, using only natural light. Reygadas had spent a year getting to know the community. 'It wasn't easy to get in,' he explains. 'I spent a year trying to find the right connection.'

What's more, the cast are all Mennonites, acting for the first time, which presented problems at the outset. 'In their society, TV and cinema are forbidden,' Reygadas explains. 'Even the reproduction of the human figure isn't allowed. So I had to spend time explaining the project and let them understand it wasn't disrespectful.'

Once the community were behind the project, the shoot was very smooth. 'The community is very professional and democratic,' says Reygadas. 'They respected the individual decision of the actors.'

Silent Light screened in Competition at Cannes, winning this year's Jury Prize, ex aqueo with Marjane Satrapi's Persepolis.

Reygadas' debut, Japon, screened in Directors' Fortnight at Cannes in 2002, winning acclaim for its earthy, visceral portrait of rural life. Battle In Heaven, his second film, screened in Competition three years later, a provocative tale that won headlines for its explicit nudity and sex scenes.

'I respect Cannes a lot,' says Reygadas. 'It's a very old place. If it didn't exist, this type of launch pad would be impossible for movies like mine to go that far. I'll never forget how moved I was at the Grand Palais when I saw Alexander Sokurov's Russian Ark early in the morning.'