An international investigation led by UK police has smashed the largest Internet paedophile ring yet uncovered.
The three-year Operation Rescue, spearheaded by the UK's Child Exploitation and Online Protection Centre (CEOP), uncovered a network of 70,000 followers, sparking action by police in 30 countries.
So far, 670 suspects have been identified, and 184 arrests have been made - 121 of them in the UK. Other suspects come from the Netherlands, Australia, Italy, Canada, New Zealand and Thailand.
A total of 230 minors have been rescued by investigators, including 60 in the UK.
Announcing the results of the operation at a press conference in the Dutch city of The Hague, police said that the ring had hidden behind a legal online forum based in the Netherlands.
According to Rob Wainwright, director of European police agency Europol, investigators posed as paedophiles to gather information about the group, which used a "secret" channel called Boylover.net to distribute images and video of child sex abuse.
Among the 240 suspects identified in the UK are said to be police officers, teachers and a scout leader. One UK suspect is reported to be a woman. Police in the UK have so far convicted 33 individuals as a result of the investigation.
Commenting on the success of the operation, Peter Davies, head of CEOP, said: "The scale and success of Operation Rescue has broken new ground. By pretending to be online sex offenders and by using sophisticated computer techniques, [investigators have] managed to identify offenders and locate suspect websites."
Operation Rescue began in 2008 when investigators from CEOP and Australian police separately identified the site as a key meeting place for abusers.
Later that year, investigators tracked down the operator of the server in the Netherlands, who is now co-operating with their investigations. Europol's Rob Wainwright said the server had employed "advanced security techniques", which took police months to find their way around.
Earlier this week, UK-based online crime hotline the Internet Watch Foundation reported that the time taken for child pornography to be taken down from web sites had more than halved in the last year, to an average of 12 days.