Naomi Watts appears appropriately regal on the red carpet for Diana premiere

Diana premiere: in pictures

Australian actor Naomi Watts was in Leicester Square last night for the world premiere of the controversial biopic about Diana in which she depicts the final years of the Princess' life.

The Oscar-nominated Impossible looked suitably regal in a floor-length white gown and diamonds while greeting and waving at fans.

Watts, 44, portrays Diana's relationship with Pakistani heart surgeon Hasnat Khan, played by Lost actor Naveen Andrews, and then Dodi Fayed (Cas Anvar) before her death in a car crash in Paris.

Click here or on "View Images" for more pictures from the red carpet

The film has courted controversy in the build-up to last night's premiere, with Watts herself admitting she may have to "leave the country" following the movie's release.

The actress, who had turned down the part twice before, said of her reasons for finally accepting it: "I guess the challenge of taking on that kind of transformation and it's annoying when fear gets in the way of things.

"I was afraid to play the most famous woman of our time because of all the comparisons of people thinking: 'Oh, well she belongs to us.' How do you take possession of a character like that and also the sensitivity of it, the concerns of how the rest of her family feel about it?"

She admitted there had been no seal of royal approval yet: "I don't think so, they wouldn't make a comment."

British-born Naomi said playing the British princess had put her back in touch with her roots.

"I still feel very connected to Britain and come here a lot.

"I love London, it would be so easy for me to come back here and live and my mum's here all the time. I feel very much connected to England."

She said of the most difficult Diana mannerisms to master: "She moves her face in very different ways. That look from under the fringe was such a memorable one, we had to get that right obviously."

Also on the red carpet were Andrews, the film's other stars Juliet Stevenson and Douglas Hodge, and director Oliver Hirschbiegel.

Diana is released in cinemas on 20 October.

PA