If no rules have been broken, perhaps the rulebook requires some attention?

After claims that a sociologist abused research into paedophilia, Marcello Mega argues that topics such as 'intergenerational sex' are open to misuse.

An academic in Europe had infiltrated Ipce, an international paedophile organisation, and I was being sent their online correspondence each day. It was apparent that many members were academics, driven by a desire to persuade the rest of society that sex with children was acceptable and to influence legislators all over the world to lower the age of consent. Intriguingly, there was a clear link to Glasgow University and a suggested link to Cambridge University.

Ipce, which was originally called International Paedophile and Child Emancipation , has a website carrying information and "academic" papers that most would find repugnant, but that fall short of illegality. In one section, for example, there is advice on what type of sexual abuse is "acceptable" with a child. "If there were to be any sex play, she would expect it to be on her level and not in the adult style," it states.

However, the site, whose webmaster is Dutch academic and convicted paedophile Frans Gieles, links to about 100 other sites used by paedophiles, and many of these stray well over the legal boundaries. On one linked site I found a "paper" making the case for sex with infants. The writer claimed it was a "known fact" that babies of six months or even younger were capable of orgasm, so how could it be wrong to have sex with them?

Some members of Ipce were in regular contact under the banner IMO, Ipce Meets Online. Members discussed how they infiltrated academic conferences around Europe, promoting Ipce's views and challenging universal assumptions about the link between paedophilia and violence.

Tom O'Carroll, a prodigious correspondent, is one of the United Kingdom's most notorious convicted paedophiles. I recognised the name instantly and was interested to read his claim that he had a "useful contact" at Cambridge University.

He said he met Claire Morris, a PhD student, through a television project. She had introduced him to her professor, Richard Green, in the department of criminology. As a result of that contact, Green had invited O'Carroll to speak at the International Academy of Sex Research conference in Paris and was recommending that his students read O'Carroll's book, Paedophilia: The Radical Case, in which he advocates sex with children, including his own, as a "positive experience".

I suspected O'Carroll was talking up his influence. I left messages for Green and Morris more than once. When my calls were not returned, I contacted Nick Champion, the university's press officer. He confirmed O'Carroll's claims about Green.

The Glasgow University connection was more straightforward. Richard Yuill, a PhD student in sociology, was a member of Ipce and corresponded regularly with O'Carroll, Gieles and others. I believed he was abusing his research position. Yuill's objective was to challenge the assumption of abuse in man-boy relationships. He described himself as a boy-lover, a phrase homosexual paedophiles use to make them seem less objectionable.

He had obtained access to adult survivors of child abuse through social work departments and care organisations. On the Ipce website, he claimed that many had been grateful for the abuse.

He posted a transcript of an interview with Ray Wyre, the UK's leading expert on sex offenders, commenting: "It reveals the kind of thinking and cognitive distortions that such experts use to justify their existence and misrepresent the central issues surrounding intergenerational love and sexuality."

Acting on behalf of a Sunday newspaper, I copied this material to Glasgow University and posed questions about Yuill's research. Some 48 hours later, the university responded, saying Yuill had done nothing wrong.

His supervisor, David Evans, said academic research could look at any subject, no matter society's view of it, and lectured me that it was wrong to impose our values on others, saying that in some cultures it was normal for boys to have sex with men.

One week later, Yuill had his computer access suspended following other information I had passed to Glasgow. I was able to prove that he had warned his fellow IMO members to be careful because of my inquiry. I also passed on an old message from Yuill to O'Carroll that appeared to confirm his research was a sham: "It will take time to convince the gatekeepers of my bona fide status as researcher (ha ha!)."

I had expected that my inquiries to the press offices at Glasgow and Cambridge would be dealt with professionally. I was disappointed therefore to receive from a source another raft of intercepted emails last month that made it clear that IMO/Ipce knew all about my interest in Green and Morris and knew that I had been sent information from Amsterdam.

Disappointment gave way to anger. I asked Champion for an explanation, reminding him that the point of my questions was to establish whether Green or Morris had sympathy for the views of Ipce. The leak must have sprung from a small number of people, an assumption he accepted.

When I put the question again last week, he suggested that during a research session into media responses to paedophilia, my contact with the university had been referred to. He said that neither Green nor Morris were members of Ipce or shared its views. I was unconvinced by his explanation for the leak.

I was more angry about the Glasgow leak because I felt it had potentially endangered my source. Glasgow's press office was more open. It emerged that documents my source had faxed from Amsterdam and that I had faxed on to Glasgow for comment had been seen by at least two members of the press office, Evans and the head of sociology.

Unfortunately, I had not blacked out the number at the top of the faxed sheets. The code identified Amsterdam. One of the small group who had seen the documents had, presumably, passed this on to Yuill and I assume he alerted his friends. They then embarked on a witchhunt, threatening to pursue legal action over the breach of Ipce's privacy. Mike Brown, Glasgow's press officer, was apologetic.

Nevertheless, following an investigation, the university concluded that Yuill had not breached any of its rules. He will doubtless complete his doctorate, but those approached by him for interview might want to be aware of the company he keeps.

Had I not been outed to Ipce, my source would have been able to continue to provide material. In time, I expect this might have led to information about serious crimes or at least to useful information about plots being hatched. Thanks to two of our ancient seats of learning, the door has been closed.