The effort is part of a taskforce called “Operation Twins” set up following the arrest of a Colorado man by the FBI earlier in the year. He is suspected of being a senior member of a paedophile ring known as the "Brotherhood".
According to the BBC, an examination of a suspect’s computer revealed a photograph of seven men at their annual meeting, which they called the “Teddy Bear’s Picnic.” It was partly this evidence that led to the arrests on Wednesday, including two in Britain.
In a statement the NHTCU described those arrested as "owners, senior administrators, administrators of sophisticated hierarchical Bulletin Boards."
Detective Superintendent Mick Deats, Deputy Head of the NHTCU said:
“This operation has exposed the complex, sophisticated and organised hierarchical structure that on-line child abuse groups use to protect themselves, including their identities and the activities they are involved in, from those in the wider community, and in particular law enforcement.”
He added:
"The fact that these people have come together in the real world as opposed to the virtual world shows how their confidence has grown."
But he warned that this confidence was "misplaced" and there was no hiding place on the internet.
The lesser offence of downloading indecent pictures of children also receives punishment, no matter the excuse. Pete Townshend, formerly of rock group the Who, was arrested in the UK in January as part of the Operation Ore investigation.
Townshend admitted visiting a pornographic site, but argued that it had been for the purposes of research for his campaign against child pornography. On Thursday he was formally cautioned by the police but without charge. He will be listed on the register of sex offenders for five years.