A school IT expert caught with so many child porn photos police gave up counting has been jailed for two years.
Jeffrey Gravell, 54, of Burry Port, west Wales, was caught with more than 390,000 indecent images of children.
His secret life of crime came to an end after he stole a series of new computers from the school where he worked.
Police were called in September 2010 and when the trail eventually led to him his home was raided.
They discovered a massive haul of disks, computers and IT gear taken from the school.
IT experts examined the haul and found it contained thousands of indecent images of children. They stopped counting at 391,270.
While the majority were the least offensive category 1 images a further 709 were the highest, or worst, category 5 level.
Gravell worked managing IT at Coedcae Comprehensive School, in Llanelli, for more than a decade.
He stood trial at Swansea Crown Court in January and was found guilty of 43 counts of making and possessing indecent images and stealing equipment.
He was jailed at the same court on Wednesday by judge Christopher Vosper who repeatedly referred to the "enormous number" of images.
"I say over 390,000 images. But the IT investigators for the police simply stopped counting at 390,000 odd. They did not examine any other equipment," the judge said.
"This was an enormous number. As I understand it, it was the most that Dyfed Powys Police has ever encountered in a single investigation."
The judge said that when the computer equipment first went missing from the school Gravell had tried to put suspicion on another member of staff
When he was eventually arrested and interviewed by police he gave a false address.
"When first interviewed by police you gave your mother's address as your address in the hope that they would not search your property and find the computers there."
Passing sentence the judge said that he acknowledged that Gravell had never approached children in the school in any way.
"There is no suggestion that you, at any time, approached a child or engaged in sexual behaviour towards any child."
He jailed him for 12 months for stealing the IT equipment from the school which he said was regarded as a "high breach of trust."
He was jailed for a further 12 months for the possession of the indecent images, making a consecutive total of two years.
Gravell was also ordered to register as a sex offender for 10 years and was banned from working with children indefinitely.