A 33-year-old man caught in possession of thousands of indecent images and videos of children, as well as a 'paedophile manual,' told police he downloaded the illegal material because he was a child abuse victim who wanted to understand the mindset of abusers, a court heard.
When police raided the home of John Whatley, 33, on September 6 last year, they seized four computer devices from which they found 1,113 accessible indecent images of children that were placed in Category A - the most serious of its kind.
During Tuesday's sentencing, Sheffield Crown Court was told how officers found a further 1,300 such images that were inaccessible.
Police also found 433 accessible images placed into Category C, as well as 696 Category C images that were inaccessible.
Whatley was also found to have nine prohibited images of children, and a 'paedophile manual' which Judge Peter Kelson told the court detailed methods for everything from grooming to abusing a child.
Some of the most extreme pictures and videos possessed by Whatley showed a male child, aged between two and four-years-old, being abused.
Prosecutor Neil Coxon said that when arrested, Whatley, of Bushfield Road, Wath-upon-Deane 'fully admitted downloading the images' in police interview.
He said: "He gave the explanation that he had been abused when he was a child and that he was seeking to understand the mindset of abusers using research, and that explained the manual which ran to 170 pages."
Whatley later pleaded guilty to four charges including making indecent images of a child, possession of extreme pornographic images, possession of a paedophile manual and the possession of prohibited images of children.
Defending, John Hillis, told the court: "One of the reasons in mitigation for him possessing the manual is that he wanted to protect his niece and nephew, who live over the road from him, from what had happened to him when he was a child."
Mr Hillis added that many of Whatley's relationships had fallen apart in the wake of the discovery made by police.
He said: "His partner was distraught, and that relationship has ended.
"His family have completely disowned him."
Sentencing Whatley to 12 months in prison, Judge Kelson said: "Yours is a much more serious case than many.
"The [indecent] images of children are great in number, and are extremely serious."
He added: "That [peadophile manual] is a truly horrific document and it is almost impossible to conceive how someone could compile such a document, and then upload it to the internet."
Whatley was also made the subject of a sexual harm prevention order, which will be in place and could result in the 33-year-old being sent to prison for up to five years if he were to breach it.