LOS ANGELES - In the crime thriller Destroyer, Nicole Kidman is almost unrecognisable in her role as a Los Angeles police detective, Erin Bell, whose face shows the ravages of both alcoholism and guilt over an old case that still haunts her.

This is not the first time the award-winning Australian star has physically transformed herself for a character, of course. Putting on a prosthetic nose helped her take home the Best Actress Academy Award for the drama The Hours (2002), where she played tortured writer Virginia Woolf.

Speaking last month at a Los Angeles screening of her new film, the 51-year-old says she is drawn to parts that take her somewhere new psychologically. And she also reveals that she wanted to support a female director, Karyn Kusama.

"It's not about trying to find really different roles as much as it's about exploring emotional territory that I've never been before," says Kidman, who earlier this year picked up a Golden Globe Best Actress nomination for the film.

"I'm also always interested in examining human nature and the human psyche," she adds.

In order to do that, she feels the need to "not be trapped by my own physicality and wanting to always say I'm willing to morph into whatever is needed to play the role".

With this film, that meant playing an embittered woman who has a fraught, heartbreaking relationship with her teenage daughter, played by Jade Pettyjohn.

Kidman, who has two daughters, aged eight and 10, with 51-year-old husband Keith Urban, an Australian country singer, says: "I was emotionally really shattered by it."

She also has an adopted son, 24, and daughter, 26, with ex-husband and actor Tom Cruise, 56.

She says: "I think the scenes with the mother and daughter were the ones that grabbed me, particularly that final image where I'm carrying my daughter on my back through the snow.

"The way that was written in the screenplay - it was so simple but it really was powerful."

The unusual structure of the narrative was something she could sink her teeth into as well, although it meant multiple close readings of the script.

"I had to go back and kind of piece together all of it because the way in which it was constructed was complicated," she adds.

She is curious to see when audiences figure out the twists and turns in the tale. "It's interesting to see whether people see all the little details because this is sparse in a lot of its dialogue and even in the flashbacks. But there's so much information in the flashbacks."

Kidman's star has grown even brighter in recent years - her critically-acclaimed turn in the television drama Big Little Lies (2017) won her the Outstanding Lead Actress Emmy, and last year's superhero hit Aquaman, in which she played Queen Atlanna, was her highest-grossing film to date.

But she wants to use that star power to support "different genres and female directors" when she can and that is a big part of why she took on Destroyer, a low-budget indie directed by Kusama, a Japanese-American woman and a relatively obscure name,

Kidman says she is all too aware that women account for just a handful of film-makers in Hollywood - only 8 per cent of the top 250 movies in the United States last year were directed by women, down from 11 per cent the year before.

Then there was Kusama's drive to see the project through. The 50-year-old director's breakout hit was the indie drama Girlfight (2000).

Kidman, who has worked with legendary film-makers such as Stanley Kubrick (Eyes Wide Shut, 1999), says: "The first thing I notice is the passion of the director. So if the director is completely consumed and passionate, he or she is my kind of director."

Kidman says of Kusama: "Her determination, desire and desperation to get this film made - because it was very hard to get it financed and made - comes from being a woman who hasn't had the same opportunities as a lot of her male colleagues.

"And that's fantastic because it's palpable."

Kidman adds: "There were a lot of situations in the making of this film where she was just like, 'Give me the chance'. And being able to help a director have a chance is a fantastic thing as an actor. I'm very proud that she got it made and that I was able to be in it."

Destroyer is showing in cinemas.