He looks the most unassuming man - small, round-faced, overweight, with a soft voice and gentle manners. Yet, or perhaps because of this, Ray Wyre probably knows more about paedophiles or perpetrators (the politically correct term for child abusers), what makes them behave as they do and how they might, just possibly, be persuaded to behave differently, than anyone else in Britain.

He is a controversial figure, and not only with the 'hanging's too good for 'em' brigade. He founded the Gracewell Clinic, the first residential clinic for the counselling of child abusers, but now closed. His admirers believe his methods plumb the deep wellsprings of paedophile behaviour, which must be the first step towards learning how to change an abuser's sexual orientation.

His detractors call him self-seeking, publicity- hungry and voyeuristic. Wyre does give occasional interviews; but our meeting was at my request, not his, while the book he is writing about Robert Black, a chronic child-abuser recently imprisoned for murdering three little girls, will publicise Black's techniques of child-seduction as a warning to parents. If it is read for other, prurient reasons, that is no fault of his.

Wyre's expertise is much in demand. 'I talk to police during their training, lecture at Birkbeck College, and meet individuals who want to speak to me: sometimes offenders, sometimes victims. Another third of my time is spent with the police, helping to catch offenders.' He lectures for 100 days a year in this country alone on how to recognise abusive behaviour and induce the perpetrators to confess and, perhaps, change their ways. When we met he was about to fly out to South Africa to advise Nelson Mandela on how abusers might be treated.

Ray Wyre says he had a happy childhood, and it would be simplistic to assume that his work must be motivated by personal memories of pain. His father was a chief petty officer; Ray joined the Navy aged 15. 'I was used to the Navy and its disciplines controlling my life.' He and his wife, Shirley, were married when she was 18 and he 20, and two weeks later he went to sea. She knew when she took him on that he would be an absentee husband. Nowadays she works with him, and they have been happily married for 22 years. They have two grown-up sons and a startlingly pretty 15-year-old daughter. As we talk Shirley, cool and sporty in a pink aertex shirt and white shorts, brings us a tray of tea.

'The children have grown up knowing that I worked with sexual crime. Obviously my work is about being suspicious and careful, but I don't think I'm over-protective. They take the mickey out of me. They don't always tell their schoolfriends, but I have determined not to let my work, or other people's suspicions and innuendo, affect the way I behave towards my children.'

They live in a small private close in a suburb of Birmingham. There is an array of Father's Day cards along the sitting-room windowsill; two plump, comfy sofas face the television, and beyond the plate-glass window a small back garden is patrolled by a watchful black and white cat. It looks the very epitome of decent family life; normal, nondescript, unthreatening, the sort of safe home that Ray Wyre is dedicated to protecting.

He says the public never gets to know of the real horrors that are done to children. The details seldom emerge in open court, often to protect the parents - assuming, of course, that the parents are not the abusers which, in 27 per cent of cases, they are. Stepfathers and male cohabitees account for another 26 per cent; so the greatest danger to small children actually lies within the bosom of the family.

According to the NSPCC, the number of children registered as sexually abused rose 12 times between 1983 and 1987. The 'overwhelming majority' of the parents were white. Many of the families were unemployed. Estimates of how many children are abused range from one in 10 to one in four girls and one in six boys. But if even one in 100 small children is abused, that constitutes a huge problem demanding urgent attention. Wyre says, 'We're messing around in a rock pool and it's a bloody ocean out there.'

The trouble is, much of the attention is directed at the wrong people. Cases such as that of Robert Black incline the public to believe that 'stranger-danger' is the greatest threat. In fact, out of 77 children under five who were killed in 1991, not one was killed by a stranger. Public paranoia reaches fever pitch during trials, but this deflects from the real problem: the abuse of children by people close to them. 'We catch one Black a decade,' Wyre says.

He had several sessions with Black in prison and came close to coaxing from him a confession that he had killed Genette Tate, the 12-year-old Devon girl who disappeared on her bicycle in 1978 and has never been found. By being soft- voiced, non-threatening, by unravelling Black's own troubled childhood, and above all, by pretending that he knew the truth already and was merely confirming the details, Wyre cajoled Black into more revelations than he had made before.

He doesn't hate and despise his clients, although the public at large does. 'I use the word 'privilege' to describe my work with people like Black. You see the waste of their potential and you can be angry with them, yet still show you care: as you must if you want to maintain a rapport. Your overriding motive is the hope that you may be able to stop this person from ever doing it again. If someone had worked with Robert Black when he started offending at the ages of 14 and 19, maybe those children would be alive today. Clearly all this affects me: it's often very sad.'

Ray Wyre was medically discharged from the Navy because of problems with his feet. 'I then went to Bible college and became a volunteer warden at a working men's hostel. I was also helping as a trainee probation officer at Winson Green prison, where my first client happened to be a sex offender. I knew that my future lay in the probation service.

'From 1981-86 I worked with sex offenders in Albany prison on the Isle of Wight, always fighting the system, because nobody wanted me to do this sort of work. They thought sex offenders were one-offs and wouldn't do it again; they didn't understand that it's a lifelong pattern of behaviour and unless people go through therapy while in prison they'll go straight out and resume where they left off. I moved to Portsmouth and set up a hospital-based programme, and in three months went from none to 20 clients. They were all on probation; they had to volunteer.

'By this time I had resigned from the probation service and become a self-employed counsellor, earning pounds 50 for two days' work. Eventually my accountant said, 'Ray, I don't know how much longer this can go on.' I said, 'Do you know anyone who'll give me a million pounds?' and he did. That's how I met Trevor Price in Birmingham, who enabled me to buy Gracewell Lodge and recruit people who had experience with sex offenders, and open the clinic.

'It's important to recognise that while some do, a vast number of abused children don't go on to abuse. Equally, I've worked with people who had deprived childhoods, yet were never abused. Research is needed into other factors: how does the grooming, seduction and manipulation of children take place? Because sex abuse is a relationship, a corruption and a violation, never just an incident.'

He responded angrily when I asked whether children could be sexual of their own accord. 'Of course children are sexual, every parent knows that; but sex between children and adults is inappropriate, and parents have a responsibility to preserve that distance.

'There are no circumstances in which a pre-pubertal child can be in a sexual relationship with an adult which is not harmful, and which is voluntary on the child's part. To me, this is not an academic debate. When you see a film of a man putting his penis into a child's mouth, the child chokes, doesn't it? Yet the abuser will say, 'It was just a blow job, guv]' Words sound so innocuous. To us, 'oral sex' means something pleasurable. To a child, it's invasive and disgusting.

'Whatever it may look like to the abuser, sex abuse is about corruption. Of course there are children who will strip off and ask for pounds 20: but that is the result of early corruption. The child is never a willing accomplice, and the more provocative or promiscuous a child, the more it needs love and boundaries.'

He then said something that throws into question the whole process of the detection and prosecution of adults for child sexual abuse. 'The NSPCC did a study, and 100 per cent of teenage girls who had been abused wished they had not told. The spotlight of the trial, therapy and counselling make the initial abuse worse for the child.

'We've got to develop agencies working with the child abuser and the mother for the good of the children. Getting the man out of the house only means he goes to another house and starts again. I wouldn't have founded Gracewell if I didn't think that.' I asked, as many people have, why not imprison repeated abusers for life, rather than risk damaging more innocent children?

'One, if a person knows they're going to get life for abuse they are quite likely to kill the child, in an attempt to lessen the risk of being caught. Two, you remove any brake on the abuser's behaviour, any attempt to control or modify the abuse. And three, if you care about and love children, what you do to the people who abuse them is crucial: and they won't 'tell' if they know the outcome is life imprisonment.

'As it is, the effects of an accusation of abuse are already devastating. Your home is broken up - your mother's crying, your brothers and sisters are crying, your father is leaving - your whole world is shattered, and you feel it's your fault.'

What about castration? 'Men can penetrate children with many things beside the penis, some of which do even more damage - broken bottles, for instance. Physical castration solves nothing.'

Wyre is made angry by the ordeal that children must endure if they agree to testify in court. 'Because of the nature of our criminal justice system, whereby an accused person is innocent until proved guilty, the defence barrister can manipulate, cross-examine and confuse a child. Then, if the accused is not convicted, the child is branded as a liar.

'That's the problem with taking sex abuse cases to court; it is grossly unjust to women and children. We're only getting a 3 to 5 per cent conviction rate. I have written reports which include a full confession from the man, yet they can't be used until he's found guilty. But there's been a backlash against child abuse cases, and now the child tends to be disbelieved.'

On the wall behind the sofa on which he sits hangs a picture of Gracewell. Always controversial, it was much disliked by factions on Birmingham City Council.

'Gracewell was shut down by the planners last December, which was an outrage. I had 21 staff, and had negotiated with the regional health authority to open a nursing home, a day centre and a hospital, and they got permission from central government, and I was so pleased. But then the local councillors in the planning department shut us down. Worried about their own re-election. No votes in sex-offender counselling, you see. You've more chance of splitting the atom than of dealing with prejudice.

'You have to change the way abusers think about their behaviour. There's one group who believe that they enjoyed sex as children: they hold on to that belief because it justifies what they do. Many more can't enter into adult relationships. They feel inadequate and inferior. Children are passive, non-threatening, you have total power over them.

'I am motivated by curiosity. I'm fascinated by people, I want to know how they tick and how I tick. It's a journey you're both on, together; therapy isn't something you do to someone else. It's about trying to get through to people's feelings.'

Does he see any cause for optimism?

'I do see change, even if it isn't going to be completed in my lifetime. I think society is more caring than it's ever been. It's amazing that we've moved away from structural abuse (child prostitution, child labour) to individual abuse.'

'I work with corrupt people, and I find innocence important. Even with sex offenders, you must help them to hold on to what's good about themselves as well as getting them to face what is abusive. You're always working with paradox, using the two opposites and finding truth in both. I think we can all do great good and great bad. I just want to help people to do what is good.'

(Photograph omitted)