A film about illegal immigration into the US and another on the aftermath of hurricane Katrina have emerged as the big winners of the Sundance film festival.

Frozen River, the directorial debut of Courtney Hunt, was awarded the grand jury prize for drama.

And Tia Lessin and Carl Dean's Trouble the Water was named as best documentary by the five-strong panel in Utah.

In Frozen River, two women team up to smuggle Mohawk Indians across the Canadian border into America via the treacherous St Lawrence river.

Jury member Quentin Tarantino said the film would be among the best thrillers he watched all year.

"It took my breath away and then somewhere around the last hour, it put my heart in a vice and proceeded to twist that vice until the last frame," Tarantino said.

On shooting Trouble the Water, which features footage in New Orleans before and after the disastrous hurricane struck, Lessin said: "We couldn't have predicted the despair and outrage we felt.

"[But] out of that, emerged a story that is all about survival and hope."

Set up by Robert Redford for low-key, art-house films 30 years ago, the Sundance festival has been transformed into a byword for successful independent movies.

Actors Tom Hanks and Sir Ben Kingsley both attended this year's festival.

27/01/2008 16:55:01