Jacques the ripper: Why terror stalked the set of the Audiard's latest hit film

Jacques Audiard, I suggest to the French director, has something of a reputation as a perfectionist. He sits bolt upright, feigning outrage. "Really? Who's the bastard that has it in for me? That's a terrible word."

If not perfectionism, there's certainly a flavour of fastidiousness to Audiard, both in his manner – he ponders his answers, searching for the right word, the right theoretical take – and his dress sense. Wearing a cravat with his soberly cut jacket the day I meet him, Audiard tops his ensemble with the sort of narrow-brimmed fedora you might see in a 1950s French thriller. Add the pipe sometimes clamped in his mouth, and the overall look is Inspector Maigret as played by Jacques Tati and drawn by Hergé.

But there's nothing too polished about the films of the 57-year-old director. Meticulously made though they are, Audiard's five features – all crime stories, of different stripes – could accurately be described as grungy. Audiard deploys stylised, minutely evoked realism to tell stories about the dingy underside of French society, a world of rejected but rebellious ' survivors. His latest film, A Prophet, hugely acclaimed since its debut in Cannes last May, is about an inmate in a tough prison – a gauche young Arab named Malik who rises through the ranks of the jail's ruling Corsican gang to become a criminal force.

In France – where the film last month won the Prix Louis Delluc, making it that country's official Oscar entry – A Prophet has sparked debate about the state of the French penitentiary system, partly on the strength of what appears to be its quasi-documentary realism. In fact, the film is brilliantly conceived illusion: its utterly convincing prison was created by Audiard's design team in a factory outside Paris, while a cast including numerous real-life ex-prisoners brings a palpable ring of sweaty authenticity.

In common with other Audiard films, A Prophet tells a story of apprenticeship. Its anti-hero starts as a rank outsider, then – through wit and sheer endurance – clambers to the top of the pile. Similarly, Audiard's debut, See How They Fall (1994) featured a clueless innocent who accidentally acquires the skills of a hitman, while 1996's A Self-Made Hero had its protagonist build himself a dashing wartime persona from scratch.

"What interests me is how the hero turns into something before our eyes," says Audiard. "Little by little, an ordinary character comes to acquire heroic qualities. That's interesting dramatically, because you take the viewer along at the character's speed."

The ingénu in A Prophet is played by 28-year-old unknown Tahar Rahim. Rahim had previously appeared in a TV series written by one of A Prophet's scribes, Abdel Raouf Dafri: Audiard met him after a screening and immediately knew he had his star. Rahim's casting is a rare case of a Maghrebin actor playing an iconic lead in a major French film, and his quietly commanding performance earned him the best actor trophy at the 2009 European Film Awards.

A seasoned screenwriter before he took up directing, Audiard has worked with co-writers on his own films, but this time came across an existing script by Dafri (writer of the recent Mesrine French gangster films) and Nicolas Peufaillit, then reworked it himself with Thomas Bidegain. The original script, Dafri tells me, was substantially different, only partly set in prison and with Malik conceived as a darker figure, "a Mozart of crime". That version sounds even more provocative than the finished film in its use of an Arab anti-hero with an ambivalent relationship to Islam: originally, says Dafri, Malik ended up corrupting an imam. The script Audiard has filmed reflects a difference in the two writers' attitude to crime cinema: Audiard, says Dafri, "loves 1970s cinema, but the more poetic end of the scale – he's closer to Dog Day Afternoon than Scarface. Personally, I have no trouble with Scarface." Even so, Dafri is delighted with the result: "It's the relationship between the two scripts that really makes the film."

While Audiard is keen to stress that his films are works of imagination, he also describes cinema as a way of "bearing witness" – "I go out in the street and take a look around," he has said. I ask whether he sees his films as political, and he reformulates the question in terms of the very nature of screen images. "I never stop thinking about the function of cinema. Thirty years ago, there was no doubt: if you wanted a tool for making sense of the real world, using movement, the only thing you had was cinema." With digital, says Audiard, every image is shrouded in suspicion. "If tears flowed down Katharine Hepburn's cheeks in The African Queen, they were really flowing, physically. Now you doubt all the time; it's caused a fracture, so you're obliged to constantly ask questions about cinema."

A recent French article suggested that critics in France have come round to embracing Audiard's work, having previously complained of a certain "excess of mastery". "They must mean scriptwriting mastery," Audiard says. "They probably mean cinema that does too much string-pulling. I like to have a script that's extremely dense, very tight – and then to mix it up with the exact opposite, put in everything that makes it really move."

The director's father, Michel Audiard, was himself a prolific screenwriter, with 130 scripts to his credit. He also occasionally directed, although, says Jacques, "I thought he was a terrible director. But I adored his screenplays; there he was a genius. " Audiard père, however, was never too reverent about film. "He loved cinema but didn't see it as art. For him, it was literature that counted."

As for Jacques, "I'm a good Parisian cinephile. By 1980, I'd seen every film ever made – seriously! And the ones I hadn't seen, if I read such and such an article, I knew exactly what they were like." Even so, he says, he has never shared the film fetishism so common in French cinema culture. "If you asked me what film I'd take to a desert island, I wouldn't take a film at all – I'd take Proust and Shakespeare." Audiard is married, with three children, to Marion Vernoux, herself a director; the couple don't, as a rule, talk about their film projects at home. "If one of us asks, yes. But there are other things. Life, the children."

Audiard first came to practise cinema after completing his philosophy studies, having a revelation while on an editing course: "Suddenly it was as if I'd seen the Virgin Mary." Fired by enthusiasm for the craft, he worked as assistant editor on Roman Polanski's 1976 film The Tenant. While he didn't get to talk to Polanski much, he learnt one thing from the experience: "Fear – and how to handle it. I was an assistant in charge of other teams of assistants. I was scared stiff for six months."

Later Audiard changed tack, writing for the stage – which then brought him to screenwriting. He formed a production company with two friends, and he was the one who – reluctantly, he says – ended up directing a film, See How They Fall. Audiard's painstaking approach has since resulted in few films, but each a sombre gem. It was the fourth, The Beat That My Heart Skipped (a reworking of James Toback's 1978 film Fingers) that really established Audiard's credentials as an auteur.

Because Audiard first established himself as a writer, it may be that his signature as a director has sometimes been overlooked. But a distinctively nervy atmosphere governs every Audiard film, and its source is in the intense, even morbid, scrutiny that the director applies to the world. Dafri perhaps puts it best when he says of Audiard: "What interests him is all the things you don't see."

Audiard himself has his own idea about the kind of tension that permeates his work. "You'll have a first week's shooting," he says, "when all you see is terror – the actors' terror, the crew's terror, my terror. Then suddenly it changes – the actors aren't frightened, the director's not frightened, the crew are frisking around like greyhounds. Then what you have to do is work up a different fear – the fear that you need, that lies between the predictable and the unpredictable.

"If you're just doing what's written down, it's like wood," he says, rapping the table in front of him, "it's crap. You need to smash all that, and find something; you don't know exactly what, but the fear that comes with it is good. Then it all comes alive – it throbs."

'A Prophet' (18) is released on Friday. An Audiard season is running at the BFI, London SE1 (bfi.org.uk), until 31 January

Crime pays: Audiard's rap sheet

See How They Fall (1994)

Audiard's darkest film, about a relationship between two outsiders (Mathieu Kassovitz and veteran Jean-Louis Trintignant) with an obsessive manhunter on their trail

A Self-Made Hero (1996)

An elegant but trenchant satire on a delicate topic in postwar French culture: Kassovitz plays a man who fakes himself a history as a Resistance hero

Read My Lips (2001)

The only film with a female protagonist: deaf office worker Emmanuelle Devos, who forms a romantic and criminal bond with an ex-con (Vincent Cassel)

The Beat That My Heart Skipped (2005)

A breakthrough hit for Audiard, and for his star Romain Duris playing the Harvey Keitel role – from 1978's Fingers – of a pianist turned hood. JR