A judge today ordered a probe into how a firebug with mental health problems was allowed to walk out of jail.

David Turner had been in Emley Prison awaiting sentence for an arson offence after being remanded in custody.

But now a judge at Canterbury Crown Court has heard that the Dover man was no longer inside after being told he could leave.

He had been returned to the prison to complete a sentence for driving dangerously but he was also on remand awaiting sentence for arson.

“This raises issues of public protection and the welfare of vulnerable persons. This was an unusual situation and Mr Turner’s solicitors had great difficulties trying to deal with it over a Bank Holiday weekend” - Kerry Waitt, for Turner

The 24-year-old had admitted flicking matches at Tesco petrol station in Dover in September last year.

But on Good Friday, Elmley bosses set him free – despite a court order remanding him in custody to appear at Canterbury.

Now Judge James O’Mahony has ordered jail bosses to explain “how this extraordinary thing could have happened.”

The judge also issued a warrant for Turner’s immediate arrest – directing that the case officer should attempt to serve it within 24 hours.

Turner has now been arrested and brought to court, but yesterday refused to leave his cell.

In his absence he has been remanded to a secure unit under the Mental Health Act.

His lawyer, Kerry Waitt was alerted by Turner’s concerned mother, who became aware of her son’s shock release.

He said later: “This raises issues of public protection and the welfare of vulnerable persons. This was an unusual situation and Mr Turner’s solicitors had great difficulties trying to deal with it over a Bank Holiday weekend.”

Turner, of Colton Crescent, Dover, had been remanded in custody after pleading guilty to attempted arson and being reckless to people’s lives being endangered.

He was arrested after being seen flicking matches at the supermarket petrol station and later pleaded guilty.

Because he committed the crime while was on licence from prison for a 15 month dangerous driving offence he was returned to Elmley to serve the remainder of the sentence.

That expired at the weekend – but now the Governor at the Isle of Sheppey prison will have to explain to the judge why Turner didn’t remain under lock and key until he was sentenced for the arson offence.