Von Trier declined to wait for her to honour other filming commitments elsewhere, and recast the role. Two months later it emerged that “scheduling problems” would prevent her from appearing Had she wangled her way out of the deal? It seems not. But this loyalty is not always reciprocated.At the press conference following Dogville’s premiere at last year’s Cannes film festival, Kidman made a public promise to reprise her role in the movie’s two planned sequels. Finally, a year or so after the movie has been released, everybody feels free to say exactly what they like about each other – and Von Trier makes delighted, unrepentant statements about the chaos he has caused. It seems to be an essential part of his creative process: drive the cast to the brink of physical and mental endurance, capture the results on celluloid, and listen to the critics cheer and jeer the result in equal numbers.Some of his on-set mind-games are fairly gentle: on the first day of filming for Dogville, Von Trier told Kidman that he was off to look at a stash of pornographic magazines that belonged to Bettany – and left the actor to protest while he spied on the scene of discomfort from the safety of a convenient fire escape Other strategies seem more baldly sadistic. It’s more about being artistically dedicated to certain people, almost to a fault. I mean I’ll damage myself in order to help them.”Von Trier’s ability to inspire such self-destructive commitment from his casts is one of the reasons why his work possesses such merciless power.

“Lars was gentle with me – he was gentle and soft, and then he would beat me up emotionally when he felt he needed that.”Like many actors who have survived working with Von Trier, she described her experience in the language of 120 Days of Sodom: “I believe Lars is a genius, and the way he works is extraordinary: it’s so intimate People say: ‘What are you: a masochist?’, and I say, no. “One day it would be a fairytale; the next it was a nightmare,” Kidman said of her work on the same film. Unfortunately, the bed was bolted to the floor…”One can only guess at what carnage has really taken place on the set of Manderlay: the truth of what happens on any Von Trier shoot tends to take a year or two to emerge. First come the rumours of an actress being humiliated on set.

Then there’s the tricky press conference at an international film festival, with everyone on their best behaviour. Then a game of claim and counter-claim is played out through press interviews. I worked out that my head was 10ft from his head while we were asleep, and I did not want that. I wanted to be an extra 5ft away on the other side of the room. “A couple of weeks in, I tried to drag my bed away from the wall that separated my bedroom from his bedroom in the hotel. Paul Bettany, who starred opposite Kidman in Dogville, called his time on the film “eight enormously long weeks in the most depressing place I have ever been to in my life” and has described the horror he felt when he discovered that he had been allocated a hotel room next door to his director. In Dogville, he cast Kidman as a young woman who takes refuge in a small Colorado town where, after having first been taken care of by the inhabitants, she is soon reduced to the condition of slavery.

Kidman seems to have received similar treatment from her director – resolved, she says, by a three-hour slanging match in a forest. Von Trier, who is a great advocate of the restorative qualities of Prozac, also claims to be unsettled by these experiences. “I just cry,” he says, “when my name appears on the credits”.Actors tend to emerge from his company praising his genius or questioning his grip on sanity and morality.Udo Kier, one of his most loyal collaborators, says he would “do anything for him” – and since he once donned a giant, pink latex headpiece to play a bloated succubus for the director, we can take him at his word.Bjork, stung by her involvement with him on Dancer in the Dark, declared Von Trier a misogynist with a propensity for “soul-robbery”. In The Idiots, he told the story of a cult leader who obliged his followers to take part in orgies and wander around small towns pretending to have Down’s syndrome – a situation that was mirrored, inevitably, in the production of the film.In Dancer in the Dark, his Palme d’Or-winning musical, he subjected Bjork to such intense pressure that she went Awol from the shoot. Although Manderlay is set in the American South, Von Trier’s fear of aeroplanes – one of the many phobias in his extensive repertoire – have obliged it to be shot in studios at Trollhaettan in Sweden.The film’s producer, Peter Aalbaek Jensen, has insisted that none of the other Americans in the cast – which includes Danny Glover, Lauren Bacall and Willem Dafoe – have raised any objections to the content of the scene.