These images displayed in the name of art disturb me deeply

Nobody could call me one of nature's censors. Indeed, as President of the British Board of Film Classification, I have gained a controversial reputation in some circles - not least the Daily Mail - for my belief that images of explicit but non-violent consensual sex between adults should not normally be refused a licence.

Although I am tough on violence, I have passed explicit films and videos which I personally find deeply distasteful and which have no conceivable artistic merit.

My view is simply this: that the public does not have to watch such stuff, but that its availability is part of the price we pay for being adults in a liberal society.

But I know I am reflecting public opinion when I insist that child sex is a complete no-go area for the board.

Recently I refused to license a new Japanese cartoon video which shows broadly pornographic images of children, although, obviously, no children were involved in making the cartoon.

I would do so again because I am not easy about the signals that such material sends out.

After the recent Internet paedophile case which demonstrated both how widespread paedophilia is and the disgusting nature of material available at the click of a mouse, nothing should be done which might suggest that sexually charged images of children are acceptable so long as they have supposed artistic merit.

That is why I am so disturbed by this exhibition and that the highly-respected Saatchi gallery's curator, Jenny Blyth, is reportedly set to reject advice by the Metropolitan Police to remove three apparently sexually disturbing pictures of naked children from it.

It is worth considering the nature of the pictures in question. One photograph shows a young boy of about four or five urinating in the snow while his sister watches.

Others show naked children wearing grotesque animal masks.

Although the pictures were taken by the children's mother (who is now, but was not at the time, a professional photographer earning her living selling her photographs) there is a disturbing ambiguity about them.

Are they young innocents at play - happy family snaps taken by a talented and loving mother - or do they hint at something far more sinister and perverse?

One thing is clear: whether or not it is unintentional, you can read into these commercial images sensational hints of ritual child abuse as well as other perverse sexual practices.

These are, in short, disturbing images which could have caused these youngsters distress and embarrassment at the time they were taken - and may very well do so as they grow older and discover that their naked childhood antics are being exhibited as art for all the world to goggle at.

They are also the sort of pictures which could attract the excited attention of paedophiles, as well as those who have a guilty interest in the bare bodies of young children and are seeking social acceptance of their unhealthy tastes.

The Met's Obscene Publications Squad clearly hold the view that the children depicted are at some risk, which is why they are threatening to prosecute the gallery under the Protection of Children Act, rather than under the Obscene Publications Act.

The former, I must stress, is not about obscenity, nor is there any defence of artists' merit. It is about the protection of children.

Even so, much of the liberal establishment has decided that we are facing a re-run of the Lady Chatterley case in which Penguin Books was prosecuted - unsuccessfully - for obscenity, for publishing an unexpurgated paperback version of the once- sensational novel.

The initial reaction of some of the great and the good has been exaggerated and intemperate, to say the least.

For example, the moral philosopher, Lady Warnock, has called the police action 'an act of politically correct dictatorship', adding: 'I can't imagine anything more terrible than police coming in and saying this photographer can't take pictures of their own children.'

Well, we have just lived through a century in which the police in dictatorial regimes performed genuinely terrible acts. This warning is not one of them.

Alan Yentob, the BBC director of drama, said: 'The implication of obscenity has only been made as a consequence of the vice squad going to the gallery in a lumbering way.'

This remark is, I fear, unintentionally revealing of a snobbish and elitist contempt and distaste for the police, which is all too common among those who regard themselves as members of an intellectual and cultural elite.

In my experience, the police do not come 'lumbering' in like so many ignorant and reactionary Alf Garnetts.

They are a sensitive and experienced group of experts whose judgment is regularly tested when cases are brought to the Crown Court.

They know the state of public opinion, and are all too well aware that juries will simply throw out cases which they regard as trivial and out of touch.

They are also very knowledgeable about how paedophiles think and behave, and they know what turns them on.

So, at the British Board of Film Classification, I listen to the police with respect, and have learned from their judgment and experience.

I now hope that those who are about to join the crusade to defend the Saatchi gallery's right to exhibit these contentious pictures will do the same.

They should pause for a moment and give due respect to the informed judgment of the police, instead of dismissing it contemptuously out of hand.

Also, speaking as a grandfather, I hope that those who believe sexually disturbing or titillating images involving children are acceptable so long as they can be labelled art, will now consider how bogus this argument is.

It is one which I have often heard from those whose job it is to understand the warped minds of paedophiles.

Exhibits such as those at the Saatchi gallery can be used by paedophiles who can be astonishingly manipulative and obsessive, to 'groom' youngsters into accepting that perverted behaviour is normal.

They will argue to vulnerable children that exposing yourself, posturing naked in masks, or urinating in front of other people is acceptable.

After all, they will say, the children's mother took the pictures, and they are on display in a highly regarded gallery, and some of the country's most respected intellectuals were happy to look at them.

In my view, the Saatchi curator should abandon her crusade and act like any other responsible citizen if warned by the police that her behaviour was apparently unlawful.

She still has time to say to them: 'I am sorry. I will take the offending pictures down.'

Andreas Whittam Smith was talking to John Torode