An IT expert who downloaded thousands of indecent images of children from the dark web has been jailed for a total of four years and four months.

Martin Cleator was previously jailed for two years for possessing more than 900,000 indecent images - the largest cache of such images that UK police taskforce Titan, where they had been sent for analysis, had ever seen.

On Friday he returned to court to be sentenced after admitting possession of tens of thousands more still and moving images.

The court heard some of the images were of babies aged six month to one years, and others of girls aged four to six years.

Prosecutor Sara-Jayne Dodge said some of the images showed children in pain and distress - in a number they were shown tied up and in one case the child appeared to be crying.

She said in an addition to the 30,311 images identified, it was estimated there were 158,974 more - a total of 189,285.

The Court of General Gaol Delivery heard that the images were discovered after police executed a warrant at Cleator’s home in Ballaquark, Douglas, in November last year over allegations that he was in breach of a Sexual Offences Prevention Order.

The order restricted the number of internet-accessible devices that he could have in his possession.

But inside, police found a complex set-up of IT equipment including custom-built virtual hard drives that had been encrypted and password-protected - likely designed to evade detection.

The complexity of the set-up had made for a challenging and lengthy police investigation.

Ms Dodge said the images had been downloaded from the dark web.

A majority - 25,963 of the 30,311 - were of the lowest category, C, but 2,319 ranked as the most extreme in category A and 2,029 in category B. There were also images of adult bestiality.

Following his arrest, Cleator provided a prepared statement in which he fully accepted the files contained images of children and he apologised to police for their having to go through them.

The defendant, aged 53, admitted 16 counts of possessing indecent images of children and four counts of making indecent photos of children.

He also admitted breaching the Sexual Offences/Harm Prevention Order.

Defence advocate Stephen Wood described his client as a ‘damaged individual’ who suffered post-traumatic stress disorder from sexual abuse that he had suffered.

He said that Cleator was ‘unlikely to have paedophile interests’ and had carried out the offences in the ‘throes of depression’.

Mr Wood said the defendant had downloaded enormous Torrent files containing tens or hundreds of images without knowing the contents - although he would have known they depicted child sex abuse.

Cleator didn’t deliberately go out looking for an image of a six-month-old baby, the advocate told the court.

Mr Wood said his client was an IT expert for whom it was fairly routine to have a complex set up of computer equipment.

The defendant continued to have the support of his wife, the court was told.

Deemster Graeme Cook jailed Cleator for a total of four years and four months, which included two years and two months for the breach of the sexual offences/harm prevention order.

Speaking after the sentencing, Detective Chief Inspector Berry said: ‘This case marks a turning point in our digital forensic capabilities.

‘The scale and sophistication of Mr Cleator’s offending, including custom-built computer systems, presented unprecedented challenges to the investigation team.

‘The Constabulary’s Digital Evidence Unit has demonstrated exceptional dedication and expertise throughout, culminating in securing this conviction.’