Bigelow makes Oscars history as Hurt Locker picks up six awards

She described winning the award in Los Angeles as "the moment of a lifetime" and dedicated it to service personnel risking their lives abroad.

The 82nd Academy Awards also saw bookies' favourite Jeff Bridges scoop Best Actor for country and western flick Crazy Heart, and Sandra Bullock win Best Actress for her role in The Blind Side.

It meant Britain's best acting nominees and main Oscar contenders Colin Firth, Dame Helen Mirren and starlet Carey Mulligan went home empty-handed.

Firth had been nominated for the Best Actor Oscar for A Single Man and Mirren had been nominated for The Last Station, while Carey Mulligan was in the running for coming-of-age film An Education.

Bigelow looked surprised to receive Best Director and appeared to be shaking with emotion by the time the Best Picture award was read out.

The Hurt Locker did not break box office records, but it was praised for its gritty realism and attention to detail

On receiving the directing award, Bigelow said: "It's the moment of a lifetime.

"I would like to dedicate this to the people who risk their lives on a daily basis in Iraq and Afghanistan . . . may they come home safe."

And she praised the screenplay as "courageous".

She said: "I would not be standing here if it wasn't for Mark Boal, who risked his life for the words on the page."

Both Avatar, which has become the biggest-grossing film in history, and The Hurt Locker came into the awards with nine nominations each.

Receiving the Best Picture gong, Bigelow said she wanted to make "perhaps one more dedication to men and women all over the world who, sorry to reiterate, who wear uniform, but even, not just the military . . . firemen, they're there for us and we're there for them."

The Hurt Locker also won the original screenplay award, as well as picking up gongs for sound editing, sound mixing and film editing.

Avatar won prizes in the technical categories for visual effects, cinematography and art direction.

Cameron and Bigelow were married for two years between 1989 and 1991 and remained close friends after their divorce.

Ben Stiller raised laughter by dressing as a bright blue creature from Avatar to present the best make-up award, his long tail getting in the way at times. The prize went to Star Trek.

It was mostly a night of disappointment for the Brits.

Nick Park's Wallace and Gromit caper A Matter Of Loaf and Death was beaten in the animated short film category by Logorama. Sandy Powell, however, took home her third Academy Award for costume design on The Young Victoria.