A man from Sheffield has pleaded guilty to downloading over 30,000 indecent images of children and possessing two paedophile manuals.

Christopher Priestley, 52, was arrested by NCA cyber crime investigators in October 2019, after he was identified as a user regularly accessing child sexual abuse platforms on the dark web.

Officers seized his laptop, desktop and external storage devices, all of which he had protected with extremely high levels of encryption. However, NCA investigators were able to decrypt the devices, on which they found the images and the two manuals.

Both manuals contained advice and guidance on sexually abusing children, including how to identify and select potential child victims and tips on evading detection by family, friends and law enforcement.

One had been produced by Priestley himself, the other entitled ‘The Paedophile Handbook’ had been downloaded.

A selection of children’s underwear was also found in his bedroom.

Yesterday at Sheffield Crown Court, Priestley pleaded guilty to three counts of making indecent images of children, namely 30,886 images in categories A-C (A being the most serious), and two counts of possessing a paedophile manual.

He will be sentenced at the same court on 11 January 2023.

Laura Scott, from the NCA’s National Cyber Crime Unit, said: “Priestley sought out and downloaded an astounding haul of child sexual abuse material.

“Every horrific image showed the real world abuse of children, each of whom was subjected to unimaginable suffering and then re-victimised each time that image was viewed.

“We know there is a direct link between online offending and contact abuse and in this case, Priestley had handbooks which contained guidance for sexual offenders on how carry out the abuse.

“Identifying and disrupting individuals who pose a sexual risk to children remains a priority for the NCA.”