A 27 year-old British man has been jailed indefinitely for acting as an online librarian for a child pornography ring.

Philip Thompson, an unemployed man who lived with his mother in Stockton-on-Tees, was arrested as part of a police investigation into possibly the largest internet paedophile ring yet uncovered.

Police found over 250,000 images of child abuse stored on Thompson's computer.

"There is a simple message to those individuals, like Thompson, who think they can go to this website - or any space on the internet - and discuss their sexual interest in children and share images," said Jim Gamble, chief executive of the Child Exploitation and Online Protection Centre.

"You leave a digital footprint, and we will track you down and hold you to account."

Thompson pleaded guilty to 16 counts of making indecent photographs of children, seven counts of distributing indecent photographs of children and one count of causing or inciting a child under 13 to engage in sexual activity.

He will now be kept in prison until it is determined that he is no longer a threat to public safety. The minimum time he will serve will be just under four years.

"Thompson was a critical piece of this network," said Detective Chief Supt Mark Braithwaite from Cleveland Police.

"He was essentially the librarian for a myriad of images that were distributed to like-minded individuals in this country and elsewhere.

"I hope this result acts as a deterrent and sends out a clear warning that activity such as this will not be tolerated."

So far the police investigation of the internet group has identified over 360 suspects worldwide. More than 130 of these are in the UK, resulting in over 50 arrests to date.