Philip Thompson, 27, had admitted being one of the kingpins behind an internet-based child abuse ring that reached 33 countries. He was given an indeterminate prison sentence of a minimum of 45 months at Teesside Crown Court.
Thompson, of Gooseport Road, Stockton-on-Tees, Cleveland, pleaded guilty today to a total of 27 charges, which included 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.
Prosecutor Harry Hadfield told the court police raided Thompson's home in February this year and recovered two desk top computers and a laptop, as well as a selection of other computer paraphernalia.
"Forensic analysis by computer experts established that the defendant had 241,000 indecent photographs of children, being one of the largest seizures of indecent photographs in the UK," he said.
Thompson was the moderator for an online forum used by paedophiles across the world to trade in child pornography, the court heard.
Mr Hadfield told the court: "The defendant's role was to police the website, which gave him the opportunity to transfer these images to his computer.
"The evidence recovered from his computer showed he had amassed a vast collection of indecent photographs of children.
"It appeared the defendant kept some of the most serious images to use as trading chips."
Of the near 250,000 images on Thompson's computers, more than 3,000 were of levels four and five - the worst kind of child abuse images.
During police interviews, Thompson admitted sharing the pornographic images with other like-minded people across the world and he told police how he had also set up his own two online forums.
"The Crown would say that this collection of indecent photographs and the subsequent police investigation revealed that this defendant has been involved in the distribution of these photographs for the last four or five years," Mr Hadfield said.
He added that 51 arrests had been made as a result of the investigation into Thompson and inquiries were continuing.
