Actress Naomi Watts has revealed she suffered physical abuse as part of her preparation for a new film in which she plays a former CIA operative.
Speaking at the Cannes Film Festival, the 41-year-old said she had spent a "fascinating" two days at Camp Peary, the US military training facility nicknamed "The Farm".
"On the first day as he kicked me in the shins and threw me down I said 'Ow', as you do," she told reporters, referring to an unnamed instructor. "They were like, 'None of that'."
The British-born star was speaking after the first screening of Fair Game, a film about the true story of CIA agent Valerie Plame, whose cover was blown after her husband - played by Sean Penn - criticised Iraq war policy.
According to director Doug Liman, Watts went to "a place where covert officers get trained". "It was the real deal that she got exposure to," he continued.
The film-maker said he himself had had a "sample" of what his leading lady endured. "I went through the first couple of hours before they kicked me out," he explained.
"Just before I left I was handcuffed with a bag over my head, with people yelling at me. But that was nothing compared to what [Naomi] went through.
"They were just giving me the kiddie part of it."
Fair Game, released later this year, is one of 19 features in contention for this year's Palme d'Or prize.
The winner will be announced on Sunday at the 63rd Festival du Film's closing ceremony.
Based on books by Valerie Plame Wilson and her husband Joseph, Fair Game is the only US title in the official competition line-up.
Its British co-writers, though - playwright Jez Butterworth and his brother John-Henry - do not hesitate from depicting Bush's administration as one with no compunction about elaborating or even fabricating evidence in order to support an Iraq invasion.
Asked if former vice-president Dick Cheney and senior Bush advisor Karl Rove had seen the film, Jez Butterworth - author of award-winning play Jerusalem - joked that they had and "love it".
He and his sibling, he added, took on the film because "it seemed impossible and involved such an amount of research".
"We're both English and it wasn't a subject we were versed in. We took it on because of the challenge."
Not a 'political movie'
The film is sure to attract criticism for its focus on an outspoken critic of the Bush regime who has taken legal action against Cheney and others for allegedly leaking her identity to the press.
It may also raise hackles in some quarters for its portrayal of Lewis "Scooter" Libby, the former Cheney aide subsequently indicted for his role in the leaking affair.
Yet Liman, whose other films include Swingers, The Bourne Identity and Mr & Mrs Smith, said he had not set out to make "a political movie".
It was, he added, "a story of two incredible characters who found themselves in the middle of a massive political scandal".
"I'm not sure I was trying to be that opinionated about it as much as trying to convey what it felt like in America at that time.
"This was not an advocacy film. I didn't have a purpose beyond wanting to tell this story and feeling it was important."
Watts echoed those sentiments, saying her focus had solely been on doing Plame Wilson's story justice.
"I found her incredibly inspiring, how she dealt with this massive change in her life," said the actress, who has also been seen at this year's Cannes in Woody Allen's You Will Meet A Tall Dark Stranger.
"Not only was she betrayed, but she was betraying others. The repercussions were massive."
Penn did not travel to Cannes with Fair Game, opting to remain in the US and attend a Senate committee hearing in Washington DC about the Haiti crisis.
His director, though, was full of praise for the two-time Oscar winner, calling him "probably the greatest living actor".
"Life for him must be very tough because everyone expects him all the time to be extraordinary, and the reality is he continually is."