A "cynical and manipulative" man from Bushey has been jailed for possessing hundreds of thousands of indecent images of children and babies.

Gary Riley, of Sparrows Herne was sentenced to four years in prison at St Albans Crown Court on Wednesday after previously pleading guilty to 20 counts of making, possessing and distributing indecent images of a child.

Prosecutor Simon Wilshire told the court how the 54-year-old was found in possession of 142,763 photographs and 844 indecent movies of children as young as six-months-old being sexually abused.

Of the 142,763 photographs, 7,980 were category A images often involving penetration. Of the 844 movies, 318 fell into category A.

Judge Jonathan Carroll said that Riley is a "cynical and manipulative" man who abused the trust of people to create disturbing photos.

Riley was convicted of 17 counts of making indecent photographs of a child which included three movies, two counts of possessing indecent images of children on and before January 26, 2015 and distributing indecent images of children between November 20, 2013 and June 10, 2014.

Riley stored the pornography on hard drives, which were found hidden behind the skirting boarder in the kitchen at his home in Bushey, following an investigation launched by Greater Manchester Police.

The investigation began with the police trying to trace a user going by the name of Teenlover50 on a file sharing website.

They managed to trace the user to an Apple computer, which was registered at Riley's mother's address.

Following a search of his home, Riley, who was already on the sex offenders register for a conviction of voyeurism, making and distributing indecent images of a child, was then arrested in January this year.

From the images found, a substantial amount were pseudo-photographs - innocent images which Riley had taken from either facebook, a camera lent to him and a mobile phone and manipulated them into indecent pictures.

There were more than 1,000 images found of one particular victim and 190 images of another six-year-girl.

Mr Wilshire said: "When Riley was being interviewed he admitted using the website but had no recollection of making pornographic images.

"He said he had a soft spot for one of the victims and cared for her as if it was a relationship."

The fathers of two of the victims were also present in court. Mr Wilshire said how both fathers had given statements about the "horror" Riley's action had caused their family and how he had abused their trust.

He also referred to a police report which stated that some of the images and movies found in Riley's possession dated back to before his first conviction.

In mitigation, defence solicitor Nick Freitas said Riley was released from prison in February 2011 and only started offending again in November 2013 - he also pleaded guilty at the first possible opportunity this time.

Judge Carroll said: "Using a public wi-fi and then hiding those hard drives was a conscious and deliberate attempt by you to conceal what you were doing.

"You groomed the fathers like you groomed the victims to gain access to them and their daughters. Then you used your skills to take innocent, family photos and turned them into indecent images."

Riley, who was wearing jeans, jumper and a black coat, looked only at the judge with a fixed expression, whilst being sentenced.

"It's disturbing how little insight you have into your offending, you have shown no genuine remorse and would be a serious harm to the public," Judge Carroll added.

"You are a paedophile who is sexually motivated by young children."

Detective Sergeant Alex Warwick from the Public Protection Unit said: "The thousands images and hundreds of video in Riley’s possession covered all levels of images, including the most extreme.

"I would like to take this opportunity to sincerely thank everyone involved during all aspects of this inquiry that have helped to convict a dangerous and predatory paedophile. The investigating officer worked tirelessly to build the evidence to secure a guilty plea and I am pleased that the sentence reflects the seriousness of the crime.

"I would warn others who are involved in this type of activity that we actively seek offenders and will bring them to justice.

Riley was sentenced to four years in prison and given an extended sentence for public protection, which would be a period on licence running for six years.