Tea with the censor is a mild-mannered affair. He is welcoming and courteous, discreet both in size and in demeanour. He has clearly perfected a serious gaze, he feels free to smile when talking about pornography ratings, to ease any possible discomfort. Robin Duval is a model of tact and balance - a model, in fact, of taste and decency, of which he is our national arbiter.

Duval took over from James Ferman as director of the British Board of Film Classification (BBFC) two months ago. Andreas Whittam Smith replaced Lord Harewood as president at the beginning of last year. The careers of their predecessors had been plagued by difficult films such as Straw Dogs, The Exorcist, The Last Temptation of Christ, Natural Born Killers, Child's Play, Crash and Lolita. But Duval and Whittam Smith have been hailed as the leaders of a clean sweep at the BBFC, instigators of a period when an institution traditionally shrouded in secrecy opens itself up to public scrutiny.

Times have changed, Duval explains. There is a desire now for transparency. In the old days, people wouldn't have been interested at all in the details - or even the broad outline - of what we were doing. Now the public challenges us, saying, "if you're doing this on our behalf, we need you to explain what you're doing." We are into choice.

It sounds straightforward enough, but Britain still has the most stringent film censorship system in the Western world. Will the public want the fact of its repression forced in its face? What can of worms is the BBFC opening? Will it self-destruct under scrutiny, like the royal family? Will censorship continue with equal force but, because we are informed, be called 'transparency'? Will it be called 'choice'?

Duval is a difficult man to challenge. In his previous post at the Independent Television Commission he was criticised for being overly liberal. But here he is in a job which is, by definition, censorial. He has a deft way of dealing with ironies: in conversation, he balances out opposites in clear, slow bureaucratise. He will conduct an entire discussion in a series of even-handed subclauses and will have covered all sides before you can contribute.

A typical sentence goes like this: 'Though it is true that there is no proof - there is evidence, but that's not quite the same - that watching films with anti-social elements produces an anti-social effect in the viewer, it is also unproven that it doesn't - if you can follow my double negative - produce that.' Duval is a man who can't be wrong.

Once upon a time, Duval was employed by the Central Office of Information. He had spent a year as a film critic on the Michigan Daily in the US (his favourite film from that time is Rocco and His Brothers, his best review, he feels, was of Bergman's Persona). From there, Duval spent three years in advertising. At the COI he wrote and produced short films, and ran their documentary section. (One of his shorts won the John Grierson Prize.) While there, he was recruited by the Home Office. In the early Eighties, after the Brixton riots, he was asked to draw up a race relations policy for the prison department, which he did by forming a working group made up of black and Asian advisers. Most recently, Duval was deputy director of programmes at the ITC and had been there for 13-and-a-half years when he left to join the BBFC.

Amongst his plans for this institution are 'structured public research exercises'. A citizen's jury is due to examine the censorship guidelines from every angle. The guidelines will have to be developed, the criteria made clear, and responses invited from outside, Duval says. He speaks of changes in response to European standards, which will become more relevant to our own. Last year, the BBFC toured the country with a 'roadshow' - a selection of films they had cut and a string of out-takes to prove they had been right to censor them. Duval plans more of the same, but instead of simply showing the public what has been done he intends to put the censors' problems to the viewers and ask for their solutions.

I ask Duval for his response to people who are opposed to the very idea of censorship. I just wonder when people say that, if they really mean to encompass material in which it is evident that the content has been arrived at by cruel or illegal means. Paedophilia, for example, or savagery to animals. I ask whether these means should not be dealt with in the courts. He counters that waiting for someone to file suit is not a very efficient way of dealing with the problem. But his example highlights one of the eccentricities of the censorship laws: one would think that if a film was made of real paedophilia, what would be condemnable would be the act itself, not its representation on film. The censors only deal with representation: they just snip out the picture, as if that changed the facts.

Duval says that he is more concerned with violence than with sex and that, while there is evidence the British public is becoming more relaxed about sex, it is clearly more anxious about the increasing levels of violence. I ask him about a number of new, sexually explicit European art films. He has passed Lars von Trier's The Idiots. Catherine Breillat's film Romance hasn't come up yet, and this week's controversial release, Gaspard Noé's Seul Contre Tous, has not, on the day I speak to Duval, been given a certificate. This French film is a genuinely shocking, slick, repulsive story about a violent butcher. Much of it is told in a rabid interior monologue, and if it weren't for the subtitles the whole film might be considered violent, since the fascist sentiments of its hero run all the way through. The BBFC have had the film for some time and have delayed classification for months.

Duval says he would breach commercial confidence by talking about it, but he tells me about three scenes that are 'specifically matters of concern': one in which the butcher beats his pregnant mistress, one in which he watches a blue movie in a cinema (a scene which is itself a quote from Taxi Driver) and one fantasy sequence in which he rapes and murders his daughter. The porn scene is certainly the least offensive of the three. I ask Duval if he believes violence can be pornographic.

He coins a few slogans in response. Violence is pornographic when, for a variety of reasons, it is unacceptable. Violence is pornographic if it invites you to emulate it. Violence is pornographic if a degree of explicitness cannot be justified by context. Violence is pornographic if it is also pornographic.

The next day I receive a call from Liz Wren, who, as head of Alliance, is distributing Seul Contre Tous. She tells me it has just received a certificate - 18 - but that the BBFC have insisted on cuts. They are happy to leave the two violent scenes alone, but they insist on cutting the scene in the blue-movie house. Wren is outraged.

This is the first time I've ever talked about a censorship issue, because it's the first time I've felt that there was dissent in the ranks‚ she says. Alliance were given James Ferman's unofficial opinion that the film should be kept intact. This is Duval's first contentious film. He has passed the violence and disallowed the porn. They're going to have to look at the fact that they don't allow any hardcore imagery anywhere, says Wren. I think the Europeans are going to test this law. I think it's time.

Now Gaspard Noé has darkened his film during the sequence in question, so that it is clear to the viewer that something has been cut: audiences will see black for 40 seconds. The censor will have nowhere to hide: he will have left his mark. (This has not proved to be the case, the scenes have been blurred to remove explicit detail)