Mathieu Kassovitz: The gospel according to Mathieu

Thanks to the French hit Amélie, he's become a heart-throb. But Mathieu Kassovitz has got higher things on his mind. By Ryan Gilbey

The French actor-director Mathieu Kassovitz, who is 34 years old, with big brown eyes that Bambi would kill for, is loitering in the reception area of the French Embassy in west London. "It's my shack," he grins, gesturing to the tall windows and many-armed chandeliers with one hand, and helping himself from a bowl of chocolate-coated Brazil nuts with the other. "But it's not easy to smuggle call-girls into a place like this."

We cross the drawing-room to inspect the gleaming grand piano. "Is it a Steinway?" he wonders. He raises the lid, and we tilt our heads to inspect the signature, which neither of us can make out.

"Know anything about pianos?" he asks after a moment.

"No."

"Me neither." He gives the piano a hearty tap with his knuckles. "We're so deep in the French bourgeoisie here," he sighs, half to himself, as he surveys the room. "So deep you can't breathe."

The last time I met Kassovitz was in 1997. He was confidently maintaining two parallel careers: acting for other film-makers, as well as directing his own scripts. He had won acclaim with his second feature, La Haine (1995), a stylish drama set on a riot-ravaged housing estate in the Parisian suburbs. Reaction to the picture was split between those who were relieved that someone had dared to lift the lid off this boiling pot, and others who recoiled from its merciless heat.

Kassovitz himself was investigated by his country's newspapers, who could not reconcile the film's tough subject matter with its creator's upbringing on the right side of the tracks. "I was naive enough to think that the movie would provoke discussion," he reflects now. "But all the media were interested in was whether we had got any trouble from the street kids. Someone even brought out a dictionary of slang from the script. And that wasn't why I made the movie."

To settle the score, Kassovitz wrote, directed and starred in Assassin(s), a violent thriller about misrepresentation-by-media. One disapproving commentator observed: "No one could really want to sit there and watch it to the end." Actually, those are Kassovitz's own words. "It was like going down into Hell. I was submerged in violent feelings the whole time I was making it. I still have nightmares about it."

His description of the trip to Cannes to promote the picture has masochistic, even kamikaze, overtones. It sounds now like he was actively rejecting the approbation that he had received in 1995 when the same festival named him Best Director for La Haine. "I went there very arrogantly with Assassin(s). I knew people would be insulted. I had made a movie that was designed to drive the audience out of the theatre before it was finished, because I didn't want them to relate to the violence in it." The movie was universally despised. So, in a sense, it was a success: the experiment worked. "Yeah. I did what I wanted to do. I pissed people off."

Kassovitz is not likely to make the same mistake again, or to need to. After Assassin(s), he spent two years in Hollywood soaking up the industry's professionalism, and returned to France as a responsible businessman. "I have to take care of my career now and blend in more," he says, making it sound like a mantra. "If you screw up too many times, you don't get to make another movie." He has even passed on some of his new-found acumen to his father, the director Peter Kassovitz, who had given Mathieu his first acting role at the age of 11 in Au bout du bout du banc. Kassovitz père was trying to get a television film, Jakob the Liar, off the ground, until his son convinced him to aim higher.

"My father is very naive. I said to him, 'this is a role for Dustin Hoffman or Robin Williams. Leave it with me'. A month later, Robin Williams had signed up to do the movie."

It seems improbable now, but the formerly impudent Kassovitz has been fully redeemed in the eyes of his countrymen. First he made a mainstream thriller, The Crimson Rivers. Now he appears in the box-office smash Amélie, Jean-Pierre Jeunet's sweet-toothed fable in primary colours. Kassovitz's role is minuscule – he plays a mild-mannered sales assistant in a sex shop, with whom the winsome heroine (Audrey Tautou) becomes romantically obsessed – but this is a movie that has inspired so much goodwill in France that it can only be a matter of time before the film's dolly grip is presented with the Order of Arts and Letters.

Some dissenting voices have complained that all non-white faces have been removed from the Paris depicted in Amélie. One critic even accused the picture of resembling Fascist propaganda, and Kassovitz is not slow to reiterate his widely voiced threats of violence to the offending writer. "Bad critics I have no problem with," he spits, "but this guy is stirring up trouble. I just want him to know I'm gonna smack him." In fact, the accusations are wide of the mark. If anything counts against Amélie, it will be that in the midst of its ripe, fantastical conceits, there is a resounding Forrest Gumpness, a triumph of dumb benevolence over passion, intelligence and pain. It's like Zazie dans le Métro without the naughtiness, or an anti-intellectual Céline et Julie Vont en Bateau. Despite its undoubted charms, it really is just a pretty face.

For his part, Kassovitz attributes the success of Amélie to the fact that "people dream the same dreams all over the world". Its popularity is particularly comforting to him, given that the film was not selected for Cannes this year. "I ended up on the jury," he says indignantly, "and believe me, all the French movies sucked."

He took the part to work with Jeunet, but he was under no illusions about what was required of him. "On a movie like that, it's not really acting. Jean-Pierre would say, 'Run from here to here, then we'll do your close-ups, first like this [smiles coyly], then like this [assumes expression that suggests enchantment or a recent lobotomy]'. I just had to not make too much noise, and hope that I didn't get a pimple when they put the camera on me."

When we met before, Kassovitz had assured me that acting was merely a hobby to help him become a better director. "[With acting] you get money, comfort, girls," he had said. "But it's not that creative." It was a candid admission, if only because his performances in Jacques Audiard's films Regarde les hommes tomber (1994) and Un héros très discret (1996), both of which found him introducing ambiguous tones into a little-boy-lost persona, were so striking. Meanwhile, his acting work in his own debut feature, Métisse (1993), had won him Most Promising Young Actor trophies from places where you wouldn't even think they had electricity, let alone film festivals. Even when he turned up for a 30-second cameo as a giggling mugger who attempts to rob Bruce Willis in The Fifth Element (1997), he brought several hundred volts of mischief to the screen.

He has continued to act – next year he will be seen alongside Nicole Kidman in Jez Butterworth's much-delayed comedy Birthday Girl – but is still blithely dismissive of his experiences. Even his collaborations with Audiard are brushed aside. "I was being told what to do but I didn't really know what was going on."

But while playing a Vatican priest in Eyewitness, the new picture from veteran provocateur Costa-Gavras, Kassovitz had something of an epiphany. "That is the first time I ever felt challenged while acting," he enthuses. "This priest who found out what was happening to the Jews in the concentration camps – here was something that I could feel and relate to with passion. I felt the weight of history on my shoulders. And when I did something good and worthwhile on the set, I would go home with a hard-on." The vulgarity only sounds more sincere for being utterly inappropriate. When you watch Eyewitness, you can say to yourself: "This is the film that gave Mathieu Kassovitz a hard-on". And when you see Amélie, you can say: "...and this is the film that didn't".

'Amélie' is released next Friday. 'Birthday Girl' is showing at the Regus London Film Festival on 21 and 22 Nov. 'Assassin(s)' and 'The Crimson Rivers' are screened tonight and tomorrow at London's Ciné Lumière