John Kavanagh Wymark-Hoar, 72, was recalled to prison for the new offences after being released part-way through a lengthy jail sentence for possessing and distributing pornographic images of minors, some as young as five.
That sentence of three years and eight months was imposed in 2017 but the pensioner, from Malton, was released on parole the following year, York Crown Court heard.
He was soon back up to his old tricks, however, and was arrested again “very soon” after his release from prison, when police swooped on his home and seized his laptop, said prosecutor Matthew Collins.
It was found that Wymark-Hoar had been using creepy, prohibited aliases for usernames and passwords to access certain websites.
This was in breach of police notification requirements after Wymark-Hoar had been placed on the sex-offenders’ register for life and made subject to a sexual-harm prevention order for his original crimes in 2016.
Mr Collins said Wymark-Hoar used online aliases such as “Yorkshire Coast Nudist” and “York Nude Guy”.
He was recalled to Hull Prison and charged with eight new offences including three breaches of notification requirements and possessing a prohibited, or cartoon, image of a female child that was sexual in nature.
He initially denied the charges and a trial was set for July, but ultimately admitted the three breaches and possession of the prohibited image in August.
The breaches occurred between September and November last year when Wymark-Hoar failed to comply with the notification requirements in that he did not inform police that he had been using aliases on the internet.
He appeared for sentence via video link on Friday, when the four remaining charges - including possessing and making indecent images of a child and possessing an extreme pornographic image - were not pursued by the prosecution and allowed to lie on file.
The court heard that Wymark-Hoar was arrested for the new crimes after police searched his home in Whitwell-on-the-Hill in January or February this year.
They seized a laptop on which three highly-suggestive passwords or usernames had been used on websites such as “Fab Swingers”, “Fab Guys.com” and “Cottaging.co.uk”.
The married ex-social worker’s depraved online activities dated back to at least 2011, when he was given a 12-month suspended prison sentence for 29 counts of possessing sexual images of children.
In 2012, a social-workers’ disciplinary panel ordered that he be struck off because of his illicit online behaviour.
He was finally jailed in 2017 for possessing and distributing indecent images of children, possessing prohibited images of minors and extreme pornography, and breaching a sexual-harm prevention order.
David Camidge, for Wymark-Hoar, claimed that the ex-social worker had now “turned a corner with regard to child sexual exploitation” and was making progress on his original order.
Imposing a new nine-month jail sentence, judge Simon Hickey said he had noted Wymark-Hoar’s previous similar offences and the fact that he had committed the new offences while on prison licence for the original crimes.
He said it was clear that Wymark-Hoar had set up the alias “to facilitate your (illegal online) behaviour”.
In addition, the judge made a new sexual-harm prevention order, which will last 10 years and is designed to curb and monitor the pensioner’s online activities.