Emilia Fox knows all about Famous Daughter Syndrome. Her parents are actors Edward Fox and Joanna David, she is the niece of actor James Fox and film producer Robert Fox, and her grandmother Angela Worthington inspired Noel Coward's 'Don't Put Your Daughter on the Stage, Mrs Worthington'. She is a casting agent's dream. In fact her aunt Celestia Fox is a famous casting agent.
Little wonder her career has looked so effortless. A role in 1995's Pride and Prejudice while studying English at Oxford led to the lead in ITV's Rebecca opposite Charles Dance. For a time you couldn't open a glossy magazine without seeing Fox modelling Jasper Conran ballgowns or sharing her beauty secrets. Male reviewers rhapsodised about her 'tinkly-precise voice' and slender frame ('like a doe-eyed baby deer') while a brief engagement to comedian Vic Reeves, during the making of Randall & Hopkirk (Deceased), catapulted her into the tabloid spotlight.
It was easy to dismiss Fox as a member of the spoilt West London boho set (Sadie Frost with more A-levels?). Even she admitted: 'I have no scars, no stories of horror or rebellion. My parents were always devoted to me.' But there was no doubt the girl could act. Stephen Poliakoff cast her against type as the punkish librarian in Shooting The Past. She was a scarily manipulative daughter in Joanna Trollope's Other People's Children, while her role as the love interest in Roman Polanski's The Pianist made Hollywood sit up and take notice. And now the BBC has just announced that Fox, 29, will be joining Silent Witness for four episodes.
Given that Amanda Burton has decided to bow out as pathologist Sam Ryan after eight years, the smart money is on Fox as the new female lead, although the BBC are keen to play it down (no doubt to avoid a rash of 'Amanda versus Emilia' headlines). Fox's character -- a driven, young archaeo-pathologist - won't arrive until Burton has left. 'I really liked the way it was presented to me,' Fox admits, 'They said, "We want you to allow her to develop. We want her to come in in a very real situation, not go, Here is the new character in Silent Witness. "'Because Amanda's not replaceable and I think everyone feels that.'
There are two schools of thought about Silent Witness: either it's a poignant exploration of what happens to the body after death, or (viz French and Saunders' spoof Witless Silence ) it's appalling creaky melodrama. 'I've been watching past episodes carefully and I'm quite addicted,' Fox insists. 'The very fact that French and Saunders found something to parody means that a) it's had a huge effect on an audience and b) that Amanda has created such a solid, lasting character. Silent Witness is not just a murder-mystery thriller, it actually has an integrity, and characters are placed in huge moral dilemmas. I think it's very difficult to write mysteries around pathology which combine police work with making you think intellectually.'
Fox even attended an autopsy before filming started. 'It was a 97-year-old man, I think they do that because it would be difficult to see a younger person for the first time. Everyone was so respectful, I felt greatly comforted that you are in good hands. Even so, I came out thinking, "Oh my God, this is where it all ends." And yet at the same time it was an extraordinary realisation that we are amazing creatures and that the body is a wonderful machine that encases an indescribable spirit.'
We are sitting in Fox's trailer during a break in filming of Silent Witness. The BBC publicist and I arrive late for the interview because we can't find the unit, the photo shoot has to be abandoned because the new set is embargoed and a freak storm is threatening. 'I doubt Emilia wants to do the interview now,' the production manager warns tersely - but there she is pouring coffees, offering to carry our bags. 'I bet your editor won't want to run the interview now,' she predicts wryly. 'In fact he'll probably say, "Who the fuck is she?!"'
There is nothing remotely sappy about Fox. She recently swapped Notting Hill for Acton, where she shares a house with Jared Harris (son of Richard Harris) who she met during the West End production of Dangerous Liaisons . They live there six months of the year and have just bought a house in LA where Harris mostly works.
And she relishes playing bad girls. Earlier this year she was mesmerising in Jimmy McGovern's Gunpowder, Treason and Plot as a fanatical Protestant spy. 'I loved being so brutal and doing those bold to-camera monologues.' Her character even sacrificed her virginity to defeat the Catholic plotters. 'I've been - well lucky is not the right word - but I've done enough sex scenes not to be frightened of them. My body is certainly not Keira Knightley's, much as I wish it was, but I know it's not going to be used in a gratuitous way. Sam Troughton in Gunpowder hadn't done a sex scene before, which has happened to me quite a few times now, and it's much more nerve-racking for a man to be naked with someone he doesn't know. I felt like an awful old harlot taking this young innocent man's screen virginity from him.'
She goes on to tell a funny story of working on an Italian film where she was lying nude on a stone floor, covered in blood, while the crew chatted about lunch over her.
Of course The Pianist was Fox's great test. Playing Dorota, a young Polish woman who aids the Jewish pianist, Wladyslaw Szpilman, Fox radiated goodness - a quality incredibly hard to convey on screen. How did she manage it? 'Roman - in a word,' Fox laughs. 'He simplifies everything and makes it so clear. You honestly feel that you're doing nothing - because he takes it down to the thinnest layer of what you are. He kept telling me, "Look into Adrien [Brody]'s eyes like you're a grrroupie! Imagine he's a rock star and you're his biggest fan." And I was like, "I know exactly what you mean. And I will do anything for you!" And I suppose the innocence, the openness of being "a groupie" was the kindness in her.'
Last year was slightly rockier careerwise. She appeared in the West End production of Dangerous Liaisons which closed early. The reviews were vicious (although critics were quick to praise Fox in the Michelle Pfeiffer role). And she had just become romantically involved with Harris, who was singled out for quite the worst kicking. Was it an issue between them? 'I have to say Jared was amazing. It can be very hard when you're leading a company and you feel very responsible for it, but he really made sure I knew it was nothing to do with our relationship. He got us all up on that stage when we were all thinking, "Oh God, is everyone laughing at us?" Because it wasn't that bad a production, it really wasn't, it just escalated in a crucible of hysteria of what was going on in the West End, and lots more productions have closed since. But the amount of press we got, it was like we'd done something terrible to people.'
Friends say that Jared, who is 13 years older than Fox, is a loyal presence. He may not be a great theatre actor, but he was wonderful playing Al Alvarez in the recent film Sylvia. Her face lights up. 'Wasn't he? My favourite scene - and we weren't together when I saw it - was when Sylvia Plath is smoking the cigarette and implying they have an affair, and he has to let her down gently. It was unbelievable.' One senses the couple may have much in common - including living up to famous fathers. Fox and her father vowed never to work together - until last year when she was offered the lead in Canadian indie film, The Republic of Love, based on the novel by Carol Shields. 'Two weeks into rehearsal they said, "Actually we haven't got anyone to play your dad. Would you mind if we asked your dad?" And in fact it was great because filming was far away from home, and we both thought that if the film comes out in Canada we won't have the heat of the press going, "Ooh look, they're doing a film together. He's obviously got it, and he's allowed his daughter to be part of it."'
On set they asked to be treated as separate actors rather than relatives. But in the evening, after filming, they went out for riotous dinners together. 'I suppose because you're at home you don't have these intense conversations because you're constantly in the father-daughter relationship. And it was fascinating watching Dad work. He had every single person on set completely in love with him within five minutes and he was only there for three weeks. The Canadian actor Bruce Greenwood and I were on the outskirts of it, thinking, "My God, how are we going to keep up to this outpouring of love?". You almost wonder is it an act. But I can absolutely tell you it's not. He's the kindest, sweetest man I know.'
The other blow last year was that Fox's role in Stephen Hopkins's forthcoming biopic, The Life and Death of Peter Sellers, hit the cutting room floor. Fox was cast as Sellers's third - often reviled - wife, Lynn Frederick, but then Hopkins decided to end the film before Sellers meets her. Fox is typically diplomatic: 'Of course it was disappointing because I so enjoyed doing it. I had such fun with Geoffrey [Rush], and I had thought very carefully about playing Lynn. I wanted to represent her in a way that I though was fair - which was a very young girl being taken up in this world of laughter and light, and then finding out the reality. Peter Sellers was completely obsessed by work and it's very difficult to live with someone like that.'
But then Fox is a workaholic, too. She gets antsy between jobs, so her agent keeps her busy with voiceovers, talking books and radio plays: 'Radio is this elite world. You feel rather privileged to be allowed into it.' This evening you can hear her in a new adaptation of Anton Chekhov's short story The Duel . As the incorrigible flirt, Nadyezhda, she conveys the pathos of a woman who has abandoned her marriage only to find her lover's interest waning. 'It descends into this mini microcosm of domestic horror. You know, that feeling when the switch is flicked and you can't do anything right. You know everything you're saying grates on their nerves.'
Fox is undeniably lovely to look at (she is an unofficial muse for Armani and Jasper Conran), but does she worry that modelling may trivialise her career? 'I suppose it's about your financial worth - in as much as, are you a good actor? - and trying to embrace that. I really enjoy doing photo shoots and always have a laugh and a good day out, but you can see the damage it does with huge celebrities, whether it's courted or not. Your privacy becomes very valuable, and I think a lot of people only appreciate that once it's too late. Lovely people invite you to lots of things and of course one wants to say thank you to people who've lent you clothes, but my rule is: only go to something because you want to. If you want to see that film, then great, but don't do it just to have your photo taken because that's silly, and inevitably you get hurt by it. People start picking up on things about your life that are irrelevant.'
Five years on, she's still plagued by questions about Reeves. Does she understand why? 'Funnily enough at the time it was all a bit of a haze, now it's even more of a haze. I've got huge affection for Jim [Vic's real name]. We had such a great time together and a laugh and there wasn't anything to hide about us splitting up, but our paths haven't crossed, not that there's any reason we wouldn't want to see each other. And I'm delighted that he's married and life goes on, but I suppose people are still fascinated because the TV series came out at the same time as our relationship, it's all too easy to hook a story to something... It's that stereotype that the comedian will always have a dark side and the actress will always be neurotic, so what can you do?'
What's the worst thing a journalist has ever asked her? 'I'm continually asked by the press if I've ever stolen things,' Fox says thoughtfully. 'But probably the worst time was when I was told I was adopted.' Seeing my jaw hit the floor, she adds: 'Thankfully I felt quite confident that I'm Mum and Dad's daughter.'
· Emilia Fox is in The Duel by Anton Chekhov today on BBC World Service, 6.30pm and 1am. Silent Witness starts on BBC1 in September.