Sienna Miller: Girl about town

If all else fails she can keep turning up at premieres and award shows for other people's films

It was not, so far as I could see, in the Financial Times. But for the rest of the papers there was no much doubt about the story of the week. It was not the alleged threat to kill Muslims in the British Army. Or the relentless cash for peerages row. Or the attempts by the oil complained to undermine the Intergovernmental Panel on Climate Change. No, it was none of these. The week's great talking point was Sienna Miller's knickers. The red-top tabloids had a field day but so did everyone else. Google her and you'll find that no fewer than 393 news outlets wrote it up. The high-minded Guardian actually did the story twice.

Sienna Miller is an actress, apparently. We know that because last week she said "hopefully, all the films I've made this year will take the focus off what I'm wearing or my relationship". It was a forlorn hope. And this time it was not the fault of a brainless media obsessed with her endlessly on-off relationship with the altogether more famous movie actor, Jude Law.

No, the problem was that she turned up for the party after the New York premiere of Factory Girl, a biopic in which she plays Andy Warhol's muse Edie Sedgwick (one of four films she has out this year), wearing a fluffy jumper and a pair of black bloomers and tights. Whoops, she seems to have forgotten her skirt, mirthed one paper. The outfit was compared variously to Bridget Jones-style big knickers, the comic costume of the music hall comic Max Wall, and the outfit of the comic strip heroine Wonder Woman - though the truth was that if you are as good-looking as Ms Miller you can get away with wearing anything and still look attractive.

At least she was alone on the red carpet. Earlier in the week she had been, as they say, "romantically linked" with the rap star P Diddy, or whatever he is currently called, after the pair were snapped by paparazzi entering her hotel at 9am after a night out clubbing. Not exactly a firm purpose of amendment from the 25-year-old actress who only days earlier had been bemoaning the fact that - à la Elizabeth Hurley and Patsy Kensit - she was famous only because of who she went out with.

Miller was an unknown until she began dating Jude Law in 2004. But her idiosyncratic fashion sense swiftly turned her into a bit of a trendsetter with her billowing skirts, beads and bohemian blouses which became known as boho-chic. Since then pretty much whatever she is wearing - from vintage cardies to a stunning gold sequinned dress by Burberry - has flown off the shelves. The shops and restaurants she frequented became the latest place to be seen.

But what gave her profile the biggest boost was the on-off/on-off relationship with Jude Law. They had been engaged for just three months when a newspaper printed a lurid story about how Law had had a fling with his children's nanny who had, unhelpfully, recorded the details in her diary: "We kissed and kissed for what seemed like ages. The next thing I know, we are dragging each other upstairs and ripping off each other's clothes..." The engagement was suddenly off. (It's been on again since, and is currently off, though the bookies will give you odds of 12/1 that they will yet marry.)

Sex, at any rate, has its uses. The new film, Factory Girl, has had poor reviews - "brisk and superficial" (LA Times), "moribund " (LA Weekly), "tame" (Variety, which added that Miller was " whiny and narrowly focused"). Which may explain why the movie's publicists are now putting the story around that the film's steamy sex scene featuring Miller and her co-star Hayden Christensen, who were dating during filming, was not simulated but reportedly the real penetrative thing. " I can't comment," said the director. "You'll have to ask Sienna about it."

Miller denies it, though she is happy enough to disport herself on screen. In her first film, Layer Cake, in which she played opposite the new James Bond, Daniel Craig, she scampered across the screen wearing lingerie, a seductive smile and not much else. And in Alfie, the movie on which she met Jude Law, she got her kit off for a bit of nude painting.

"As an actress I feel that if you start to impose your own inhibitions then you are not doing your job," she once told an interviewer. " And I'm fascinated by people who are extrovert, so I guess I've got a lot more nudity to come. My breasts will feature again in a few films."

She also knows that controversy draws attention. In a recent interview for Rolling Stone - in which she made derogatory comments about the city of Pittsburgh , referring to it as Shitsburgh, for which she later had to apologise - she remarked, apropos of her Jude Law experience, that " monogamy is a weird thing for me. It's an overrated virtue, because, let's face it we're all ... animals". A swift U-turn followed. Monogamy is now something "I hugely aspire to and respect".

Both statements won her the headlines - as did her appearance the other day on a chat show in which she said Law's cheating had robbed her of her innocence. "I sort of feel like, what if I never love that vulnerably and that openly again?"

If you think that sounds vacuous, try this: "I guess when people read those things about you they feel involved in some way," she says. " It's wonderful to feel supported, but there's a lot of negative energy towards me as well. So I ignore it, to be honest. If I started to read it all it would completely mess up my head. I don't want to feel like a victim in any way. I'm proud. I think all humans are essentially proud and I certainly am... It's just so weird when an entire nation knows what you are going through."

Or: "It's reached this point where people are fascinated by every intricate detail of other people's lives. And some people are willing to give up their lives like that. You get these people on reality TV shows who are so desperate to be famous and they tell everything about every sexual experience they've had, and it seems the more that they do it, the more everyone is expected to do it: actors, musicians, everyone.

"But I don't want to share intimate details of my private life. You wouldn't meet a stranger on a bus and say, 'Oh God, I had great sex last night, let me tell you all about it.' No, because it's your business. All this is getting out of hand."

And imagine what she's like when she ventures into a culturally and politically sensitive area. One of her new films, The Interview, is a trio of stories based on the work of the Dutch film-maker Theo Van Gogh. " We're re-creating his films, in honour of his memory," she has said. "It doesn't touch upon his death; it's a remake of the films he made in Dutch. But it is political and it's kind of dangerous, I guess." You could say that. Van Gogh is the man who called Muslims "goat-fuckers", and was violently murdered by an Islamist fanatic. It's political and kind of dangerous all right.

To be fair Sienna Miller hasn't had much preparation for that kind of thing. Despite her silly name (it could have been worse, her sister is called Savannah) she is British, for though she was born in New York in 1981 she moved to England when she was 18 months old. She went to school in Ascot where she played the Angel Gabriel in the school nativity play. Her father, Ed, is a banker, and American. Her mother, Jo Miller, is a South African who ran the Lee Strasberg acting school in London. Her parents divorced when she was six.

As a teenager Miller was a photographic model but she then studied acting for a year at the Lee Strasberg Institute in New York. Returning to Britain she got a part in a television series called Keen Eddie but her break came with the film Layer Cake, before playing a supporting role to Jude Law in the 2004 remake of Alfie.

She has not made much impression as an actor. In 2005 she made her West End debut as Celia in Shakespeare's As You Like It to mixed reviews. "Just a pretty face," one review was headlined. But it kept her occupied while the "Jude Law and the nanny" saga played itself out in the press. "It helped going on stage," she said. "For three hours you inhabit another world and even though things were pretty bad, it meant that I had something else to do, someone else to be."

The intrusive media was not, at any rate, sufficiently intimidating to prevent her from turning up at the UK premiere of her film Casanova at the height of the nanny drama. She glided up the red carpet, before hundreds of photographers and journalists, wearing a strapless Christian Dior dress and a diamond choker.

She must be hoping for better luck with the other films to be released later in the year. She stars opposite Michelle Pfeiffer and Robert De Niro in the fantasy epic Stardust, and opposite Spider-Man star James Franco in the horror comedy Camille, as well as in the Theo Van Gogh film Interview, directed by Steve Buscemi.

If all else fails she can keep turning up at premieres and award ceremonies for other people's films, as she did at the Golden Globes recently. Jude Law, the word has it, is getting a bit cheesed off by her constant appearances everywhere. "It appears he thinks it's an attempt by Sienna to become a more important Hollywood name than he is," one Tinseltown gossip put it.

"It happened in reverse to the way that I would have liked it or planned it," Ms Miller has sighed, meaning that she wished she had had the career before the fame.

Sometimes you just have to try to make the best of things.

A Life in Brief

BORN Sienna Rose Miller, in New York, on 28 December 1981.

FAMILY Father, Edward Miller, an American banker; mother, Jo Miller, a South African drama teacher who ran the Lee Strasberg acting academy in London.

EDUCATION Heathfield school in Ascot, Berkshire, and the Lee Strasberg Institute in New York City.

CAREER One-time girlfriend of Jude Law, boho fashion trendsetter, actress. Films: Stardust, The Mysteries of Pittsburgh, Camille (all in post-production) (2007); Interview (completed but not released); Factory Girl (released in the US this week); Casanova (2005); Alfie (2004); Layer Cake (2004). Television: Keen Eddie (2003); Bedtime (2001).

SHE SAYS "Sometimes a girl knows exactly what she wants."

THEY SAY "Jude thinks Sienna is trying to upstage him and become a bigger name in Hollywood than he is." - anonymous "friend"