A 70-year-old man who collected and categorised the largest hauls of indecent images of children ever found in North Yorkshire has been jailed.

Judge Andrew Stubbs QC told Geoffrey Crossland, the "scale of the depravity" depicted in the 2.2 million still and moving pictures he possessed would be hard for the public to come to terms with.

Stephen Wood, prosecuting, said the vast collection - which was stored on SD cards, USB sticks, DVDs, SIM cards, floppy disks, laptops, tablets and mobile phones - was discovered when officers raided Crossland's home at Padside Green Farm, Harrogate, North Yorkshire, in October last year.

Police also discovered an "underground bunker" containing an arsenal of illegal guns and ammunition, a shooting range and metal workshop under the house's outbuildings, said the barrister.

They included 24,000 rounds of ammunition and expanding bullets. The judge told Crossland, who once ran a business manufacturing electric components for vehicles: "The risk to the public is clear to all, but that risk is increased by the volume of weapons you held and the volume of ammunition which you also held."

Crossland, of Padside, Harrogate, admitted six charges of possessing prohibited firearms, two charges of possessing firearms without the relevant certificate, two counts of possessing ammunition without the relevant certificate, and one count of possessing a shotgun without the relevant certificate.

He had previously pleaded guilty to three counts of making indecent images, one of having extreme pornography and one of having prohibited images of children.

Mr Wood said Crossland had 34,612 images in the most extreme category A, and 2,107,873 in the least extreme category C.

These had been "painstakingly categorised", many under sexual titles having been downloaded from the internet. Sentencing Crossland to 12 years and eight months in jail, the judge told him: "One issue which is not forgotten is that these images capture real life people, and at the same time real life sexual abuse being carried out on them."

For Crossland, Susannah Proctor said: "He is in essence a hard working and successful man" who had run his business for some years from the house and had a long time fascination with guns.

She disputed the suggestion that the underground complex was a "bunker" saying Crossland had constructed it from shipping containers after he applied for planning permission for outbuildings to house his business, but it was only partially granted. He had not intended the illegal guns would be used by criminals or for criminal purposes.

"He is aware there is a significant chance he may remain in custody for the rest of his life," she said.

Mr Wood said Crossland had been away on a shooting holiday in Argentina when officers searched his home on October 18 last year, having been alerted to suspicious online activity.

His wife answered the door, and more than 100 digital devices were seized and examined. Crossland was arrested as he arrived back at Heathrow Airport days later.

Detective Chief Inspector Graeme Wright, of North Yorkshire Police, said that the force is involved with "ongoing enquiries to establish if Geoffrey Crossland was involved in the direct abuse of children".

Speaking outside court following the sentencing, Julian Briggs, from the CPS, said that Crossland's collection of indecent images was "without parallel in the area".

He added: "That alone would make this case extraordinary and troubling. "But the subsequent discovery of prohibited firearms and ammunition, concealed in underground bunkers at Crossland's home, clearly shows that this defendant is a highly dangerous individual."

The prosecutor was highly commended for his work on the case by the judge, as were Det CI Wright, Det Con Nicky Wareham, and the woman who analysed the IT devices and images, Det Con Warboys.