Ex-policeman Charles Littleboy, 55, was jailed after admitting that he created, distributed and owned images of young boys suffering horrific sexual abuse.
Over six years until 2010, Littleboy, from Howe, near Thirsk, downloaded images of child abuse from the internet and engaged in depraved discussions with fellow paedophiles, the court heard.
One of the detectives involved in the case said it was the worst he had encountered in 17 years of policing.
Littleboy, known by his middle name Kevin, pleaded guilty last month to 11 counts of making indecent images of children, four counts of distributing indecent images of children, five counts of possessing extreme pornographic images and one count of possessing 3,904 indecent photographs of children.
Simon Reevell, defending said his client was a shy and private man who now faced “utter humiliation”.
Judge Fox accepted Littleboy’s reputation was ruined, but he said he failed to appreciate the “utter humiliation and degradation of the victims of your crimes”.
He jailed Littleboy for two-and-a-half years, put him on the Sex Offenders’ Register for life and banned him from unsupervised contact with children.
Littleboy is a former director of the Yorkshire Agricultural Society, which organises the Great Yorkshire Show and worked as a steward at last year’s show. He was also a police officer with North Yorkshire Police in the 1980s.
Outside court Detective Constable Karl Middlemiss of Northallerton CID, said: “This is the worst case I have seen of this nature in my 17-year career.
“The sentence reflects the serious and repugnant nature of the images in his possession.”
However the NSPCC reacted angrily to the sentence, calling it too lenient.