He claimed other people were using his kit when the new images were accessed but a jury found him guilty and he was jailed for two years at Exeter Crown Court.

Lock, 47, of Gammaton Road, Bideford, denied but was convicted of five counts of making and one of possessing more than 300 indecent images of children.

Judge Ian Lawrie QC jailed him for two years and told him: “Your explanations were nonsensical and frankly ridiculous. Your previous conviction shows you are incapable of confronting and dealing with your deviant fixation with images of children.

“It shows you have lied to the court and are a devious individual who cannot be trusted. You were the carer for your partner with very serious responsibility but you have betrayed that trust.

“Your actions have in a small way contributed to the vile trade in appalling images in which very young victims are subjected to awful and degrading behaviour which will no doubt ruin their youth and blight their adult lives.

“You continued to view these images despite a previous conviction. If you do nothing else in prison you should reflect of the effect on children right across the globe, bearing in mind the website you used was in Russia.

“You should reflect on the misery your actions have caused indirectly and try to deal with the devils within you which drive your fixation to view this material.”

During a three-day trial the jury heard how police searched the home which Lock shares with his partner on August 10, 2013, and seized a laptop from his car and a phone from the house.

One file name referred to an image of a naked 12-year-old boy.

A police expert found seven images in the recycle bin and a total of 325 images.

The internet history showed access to a Russian site named imagesource which was known to host child abuse images.

There was a bookmark on his iPhone for a section of the same site called ‘we love little girls’ which contained thousands of images, some showing illegal material.

Emails had been sent from Lock’s account within three minutes of some of the images being downloaded.