By Geneviève Roberts
Published: 05 April 2006

David Thewlis was filming Mike Leigh's Naked when Sharon Stone - and her uncrossed legs - was catapaulted to fame by Basic Instinct. While she was branded a "kinky seductress" for the Nineties thriller, Thewlis won Best Actor at Cannes for his depiction of the tortured antihero Johnny, a role he gave his life over to as he spent more of his waking hours improvising than playing himself. More than a decade later, the angst has all but gone. He's older, he's a father, and seems relaxed and comfortable. When he is not smoking with a leisurely pleasure, his hands gesture an accompaniment to conversation as he becomes animated, erupting in laughter or surprise.

He knew Basic Instinct only by reputation until he was approached to appear in the sequel alongside Stone and the British actor David Morrissey. The idea initially struck him as "dodgy" after so many years in the interim, but when he was told it would be set in London he thought it had potential. "You'd have these two grim northern blokes going, 'You dirty bitch,'" he says.

Even before working with Morrissey, "a very sharp Scouse guy", and the director Michael Caton-Jones, he admired them. They laughed throughout the project, which felt like making a British film, more Prime Suspect than Hollywood.

Thewlis plays the detective, a role he wanted to give a go, investigating whether Stone's novelist is a murderer. He mimics flicking pages of a notebook, loading the gesture with cop-on-film meaning; touching objects, any objects, with scrutinising significance. He gets the funny lines and sounds slightly surprised as he admits he "quite liked" the end result.

"It was a lot better than I expected," he says. "I thought it could be a disaster because everybody is getting ready to say, 'Why have they done it?'."

He thinks Stone is "no nuttier than other actresses, especially Americans; she's endearingly nutty". They worked together on the opening scene to the film, and despite her reputation for being demanding, he found her (he pauses) "well-behaved".

But he says he really felt for Morrissey when he saw the sex scenes on screen. "I was thinking, 'I'm so glad I've not got your part, I'm so glad I'm just the detective,'" he says.

Stone sat in on Thewlis's costume fittings, which is unusual for any actor to do for another. She was getting ties and trying them on him, tightening his belt, giving suggestions. His annoyance subsided when he realised her good taste in costume - both he and Morrissey are dressed in Moschino suits. "She was very funny, intense, passionate, bubbly, creative and quite wild," he says, though he emphasises that he had very little to do with her.

High praise from an actor who tells me Val Kilmer is a "nutjob", though not as bad as he is painted, Robert Downey Jnr "very complicated" and Marlon Brando "strange". The director John Frankenheimer, with whom he worked on The Island of Dr Moreau, has "one of the ugliest souls".

Thewlis left the set of Basic Instinct early, three weeks before his baby, Gracie, was due to be born. He didn't want to be constantly on edge, checking his phone, waiting for his girlfriend, Anna Friel, to call. To say he is excited by his daughter is an understatement, she is "fantastic, wonderful, a very, very, very good baby. We're really lucky. I know every parent is going to say that, but she's just lovely."

He has flown into London from Italy, where he has been reshooting scenes of The Omen; Friel is flying back from Prague so they can spend the weekend at their home in Windsor. She is working on Bathory, taking the title role in a film questioning Slovakia's biggest legend. The Countess of Bathory is remembered for killing 650 young virgins, but the film suggests she may be innocent. "It's a fine line between the two," Thewlis says. "You either kill 600 people, or you don't. 'Sorry, it was a misunderstanding?'"

A week without Gracie has been awful. At eight months old, she is beginning to communicate. "She says 'dada'," he says, "but she doesn't know it is me, she would say it to the ashtray."

Friel calls midway through the interview to say that her plane is delayed. I ask whether he is planning to get married. "Married, yes, one day, but no plans yet - to Anna, I stress. We talk about it, but we're certainly not going to announce anything now. We'll have more children, but for now everything's really nice," he says. "Seeing two friends get ready for a wedding, why would we give ourselves that stress as well? Everything's stressful enough with all the travel and the work and Gracie.