The seven men, who were arrested last year as part of Operation Cathedral, an international investigation spanning many different countries, first appeared at trial on January 11 as the case reached Kingston Crown Court.

The investigation, which spans five years, has resulted in the arrests of 107 people worldwide over the last two years. Police in some 12 countries were involved in the investigation, which aimed to crack an informal Internet pedophile ring known as the Wonderland Club.

In the UK, police recruited two computer consultants to work on the project fulltime for 14 months.

Membership to the club involved submitting at least 10,000 pedophile images to the "club library," which was distributed amongst members using the Internet.

Eight men in the UK were arrested last year, but one, from Norwich, committed suicide. Only one of the remaining seven, Gavin Seagers, a computer consultant from Dartford, Kent, pleaded guilty to charges of being involved in the ring.

The sentences handed down late yesterday by Judge Kenneth Macrea, have been criticized in some quarters for being too lenient. The largest sentence handed down was 30 months in prison, which several children's charities in the UK said was too short.

However, police have said that the maximum sentence that could have been handed down was three years, although the British government is planning to increase the maximum tariff for peddling pedophile pornography from three to 10 years in jail, from this summer onwards.

Police say that they seized around 750,000 still pictures and some 1,800 computer-based videos in their investigations. Detectives have been working with Social Services staff in a bid to identify some of the estimated 1,200 under-18-year-olds pictured in the images and videos.

The Wonderland Club is said to have centered on the US, where its most senior members were located, with one member having a collection of 45,000 images on his computer, while a collector in Italy is known to have had 180,000 images on his PC server system.

The club was uncovered after a US Customs investigation into the Orchid Club, a live Internet viewing organization in which members watched streamed feeds of pedophile abuse on the Internet.

Under Operation Cathedral, which was coordinated by US investigators and the National Crime Squad in the UK, police raided 32 addresses in the US, 18 in Germany, 16 in Italy, 14 in the UK, eight in Norway, four in France, three in Portugal, two each in Australia and Finland, and one each in Austria and Sweden.

Detective Alex Wood, who headed the British side of the investigation, told reporters that Wonderland was a club set up by pedophiles worldwide, and that its chairman was Harry Mudd, a US citizen who has since been convicted.

Speaking to reporters, Detective Wood said that Internet users would be very unlikely to stumble on Wonderland by mistake, as it had five levels of security, making the Web-based system well hidden and secure.

The most basic level of security involved using the word "w0nderland" in the domain name, with a zero in place of the letter "o." This meant that Web users would have be quite specific when they tapped in the domain name.

The seven men sentenced yesterday included Ahmed Ali, aged 31, who was jailed for two years after police found 12,000 images on his PC; Andrew Barlow, aged 25, also jailed for two years with 24,000 images on his computer; and Frederick Stephens, aged 46, sentenced to one year after police found 9,500 images on his PC.

Ian Baldock, 31, was given a 30-month sentence for having 40,000 images on his computer, most of them under 10 years old. The youngest person in the image was thought to have been just three months old.

Also sentenced to 30 months was David Hines, 31, who police said was the European coordinator for the Internet ring. He had 12,000 images on his PC.

Antoni Skinner, 36, sentenced to 18 months, had claimed he was recruited to the pedophile group for his computer and encryption skills.

Gavin Seagers, meanwhile, who had pleaded guilty, was handed down a two year prison sentence. he had had 46,000 pedophile images on his personal computer.