The virtual, it seems, is giving rise to an increasing worrying reality. The computer-literate Irish are proportionately the second most avid users of the Internet for paedophile activities.

According to the cross-Border children's rights group, Focus On Children, there are known Irishmen (mostly) logging on to look at pictures of children being abused, to exchange information on targeting children and to gather information from so-called "child-friendly" sites. Sean Lawless, the director of Focus, made his claims following an EU-funded research project carried out over the past year by a group of postgraduate students at Dublin City University for the charity. The students devised software capable of identifying online paedophiles across Europe.

Mr Lawless claims his organisation has more than 4,000 paedophiles' names across Europe. Though the initial aim of the project was to look just at European paedophiles' Internet activity, it quickly became clear this would be impossible, that "we would have to take in the globe".

"Over the past 12 months we were interacting with between 15,000-20,000 paedophiles worldwide. They are just the ones we know of. There are obviously more." The majority of Internet sites accessed by paedophiles are for the display of child pornography.

The political and lobbying dimension of paedophile activity is organised and the paedophiles' view assiduously disseminated on the Net. "The Paedophile Liberation Network, for instance, says it supports the UN Convention on the Rights of the Child," Mr Lawless says. "They say they are supporting the right of every child to full expression, which they say includes full emotional expression and sexual interaction with adults.

"They lobbied when the Amsterdam Treaty was being revised to have paedophilia recognised as a sexual orientation rather than deviancy, so that they could not be discriminated against. These people have the best of legal counsel."

Sites include those used to lure children - apparently devoted to film stars or cartoon characters - encouraging them to give information about themselves. There are also newsgroups where paedophile information is exchanged. These cannot be accessed through Irish providers, but can be through some European providers.

According to Rachel O'Connor, research co-ordinator of COPINE (Combating Paedophile Information Networks in Europe), the significance of paedophile activity on the Internet lies not only in its enormous capacity to distribute pornographic images, but also in the fact that, as an acceptable and accessible medium, it "routinises, sanitises and normalises sexual contact with children".

It is difficult to know if those visiting the sites are "latent abusers", she says, but there is no evidence to back up suggestions that Internet paedophiles will go on to abuse in reality. "Watching these images, though, is watching the record of a brutal criminal assault."

Arrests have been made here and in Europe. In December 1997, 50 people were detained across France in a crackdown on a paedophile ring using the Internet. Last September more than 100 people were arrested in 12 countries as police targeted the Wonderland Club, described at the time as one of the world's most sophisticated paedophile rings.

Since the introduction of the Child Trafficking and Pornography Act here in July, there has been a number of arrests related to use of the Internet for paedophile activities. The Act criminalises the possession of any child pornography.

Policing the Internet, however, is notoriously difficult. "It is challenging police forces across Europe," says Det Insp Thomas Dixon of the domestic violence and sexual assault investigation unit.

"I have no doubt that it is a growing problem here, as everywhere. Almost every country is making efforts to combat paedophile use of the Internet, but none can work alone. It requires that police forces, across Europe certainly and from the rest of the world, act together proactively."

One of the biggest problems in policing the Internet, aside from its vastness, is the fact that there is no international legislation covering it.

The US Freedom Of Speech amendment precludes a systematic crackdown on paedophile activities on the Net there. Different countries have different legal definitions of a child. In Japan there is a cultural issue where the perception of the very young as sexually attractive is considered more acceptable than in the West.

Insp Dixon also says it is something which cannot be left to the police. "It must be dealt with at a multi-agency level. Combating this requires criminal and technical expertise. It must involve researchers, Internet service providers, parents and teachers as well as the police."