A disabled man who was jailed for 12 months for masturbating in public and trying to blame it on his Parkinson's Disease was released from custody - just a month after being sentenced.

Earlier this year Robert Dills, 57, was sentenced to a year behind bars for pleasuring himself in front of unsuspecting members of the public in Paisley.

At the town's sheriff court he was also placed on the Sex Offenders' Register for 10 years for his antics, which took place in April this year.

But within weeks of being locked up Dills was back on the streets due to good behaviour rules and his sentence being backdated to when he was first remanded in custody.

His early release was triggered by the sentence being backdated to April, when he was first remanded in custody.

That meant he had already served five months of his sentence by the time he was caged.

And early release rules meant his 12-month stretch became a six-month term, meaning he only had four weeks to serve before being released back into the community.

And yesterday the circumstances surrounding Dills' case was criticised by Graeme Pearson, of the Labour Party’s Expert Panel on Justice.

The MSP, who was a police officer for 38 years and served as Director General of the Scottish Crime and Drug Enforcement Agency, said: "The handling of this case will bemuse many members of the community and no doubt anger victims across Scotland.

"Unfortunately there is little evidence here of either a proper penalty or an effort to address the issues underlying the offence."

The Scottish Government insisted Dills being released back in to society free and able to offend again after spending just a month behind bars was nothing to do with them.

A spokesperson said: “The independence of Scotland’s judiciary is a fundamental part of the Scottish legal system and Scottish Ministers cannot intervene or comment on individual cases.”

Dills was jailed following a trial at Paisley Sheriff Court.

He had denied three charges of engaging in sexual activity in the town's Broomlands Street on April 22.

However, Sheriff Fife found Dills guilty of all three charges.

He said: "Your behaviour was disgusting, despicable and completely reprehensible."