POLICE raided an address in Scotland yesterday as part of a worldwide purge on an Internet child pornography ring which netted dozens of suspected paedophiles and uncovered images of children as young as two years.

The operation was co-ordinated by the National Crime Squad and a spokesman said yesterday that there had been a raid in Livingston.

Lothian and Borders police refused to confirm the location of the operation, but a spokesman said: ''In a joint operation with the National Crime Squad, officers from Lothian and Borders police raided an address in West Lothian this morning and a report will be submitted to the procurator-fiscal.''

Some 15 addresses were raided in the UK as part of the operation, code-named Cathedral. Other countries involved included Australia, Austria, Belgium, Finland, France, Germany, Italy, Norway, Portugal, Sweden and the US.

Police said more than 100,000 indecent images of children were seized during the investigation.

The ring was originally discovered by officers from Sussex Police and the operation was co-ordinated by the National Crime Squad, with involvement from the National Criminal Intelligence Service, Interpol and the US Customs Service.

Mr Bob Packham, deputy director general of the National Crime Squad, said it had been a ''difficult and distressing'' investigation drawing on unprecedented international police co-operation. I am unaware of another police operation that has ever pulled together so many law enforcement agencies world-wide to effect simultaneous raids and arrests,'' he said.

Chief Inspector Terry Powell, of Lothian and Borders Police, has been overseeing the force's forensic computer services and he explained yesterday that, although the unit had only been up and running since June, it had already uncovered four definite paedophile cases among 14 indecency cases.

''Our experience from the first of June is that we have a heavy workload already in terms of pornography on the Internet, but we have made the decision that, however hard core the pornography, we have a more important issue to concentrate on and that is paedophilia.''

Although Mr Powell would not comment on yesterday's raid, he said that five Scottish forces had now invested in the technology which enabled them to get access to potential evidence held on computers.

''No longer will police officers ignore the computer sitting in the corner when they raid an address,'' said Mr Powell, who confirmed that computer equipment had been seized at the West Lothian address and was being examined.

At a news conference in London yesterday, officers who led the worldwide operation said 11 men had been arrested in the UK following raids on 14 addresses in London, Sussex, Oxford, Berkshire, Kent, Gloucestershire, Middlesex and Norfolk.

Mr Packham said the operation, which had been running since April, was believed to be the biggest investigation into Internet pornography so far.

He said databases containing more than 100,000 images of children had been seized. Previous operations had netted around 10,000 images.

Detective Superintendent John Stewardson, who led the operation, said it was obvious that children had been abused on a massive scale to produce material to feed the international ring which called itself the ''Wonderland'' club.

He said: ''There are people who simply exchanged material and some who produced it. We have got one producer in the UK who was part of this group.

''The children abused were of both sexes and some, it would appear were as young as two, although we don't know because we don't know who these children are yet. The content would turn the stomach of any right-minded person. It's really disgusting.''

He said the club had left a ''horrendous legacy'' through the number of children abused to feed it material.

Efforts would now be made to trace all the children involved to give them the help they needed and to assist bringing their abusers to justice.

Although the Wonderland club was set up in the United States, its activities only came to light during an investigation by Sussex Police.

Mr Stewardson said Internet porn rings previously felt they were immune to police action and that yesterday's operation would send out a strong signal that joint action by police across the world made their activities dangerous.

Yesterday's raids had led to more than 100 people being arrested in other parts of the world, including some women. There were 32 addresses in the United States and 18 in Germany.

Police in Germany said the investigations had pointed to some 200 individuals involved in making pornographic child videos made available on the Internet.

Mr George Farquhar, the deputy director of information technology services at Strathclyde University, yesterday said it was virtually impossible to police the Internet thoroughly, although service providers were becoming stricter in controlling the sites.

He added: ''Even if the controls are getting tighter, there is something like one new host added on to the Net every minute, so as soon as you take one off, they can sign up again under a different name.''

He said that there was a general feeling among Internet users that the amount of child pornography was increasing. Access was simple - ''If you went looking for it, you would find it no problem at all.''