A mental patient locked up in a secure unit after being convicted of kidnap has gone missing after escaping his guards during a supervised outside visit, police said.

David Burslam, 49, was on "escorted leave" into the centre of Doncaster from the town's Cheswold Park Hospital when he gave accompanying staff the slip, South Yorkshire Police said.

Burslam, who was made the subject of an indeterminate hospital order in 2009, is the latest prisoner to go on the run after being allowed out of detention in recent weeks.

He was last seen heading towards Doncaster railway station on foot this morning, a police spokeswoman said.

She added: "Detectives believe he may be making his way out of the immediate area in an effort to contact friends or family.

"He has friends and family in Manchester, Hull and Derbyshire but could be travelling anywhere in the country.

"Members of the public are advised not to approach Mr Burslam if they see him, but to call police on 999."

Police described Burslam as six feet tall with a "stocky, muscular build" and short mousy blonde hair.

He was wearing a dark grey coat, grey tracksuit bottoms and white trainers when last seen.

His escape came after the Ministry of Justice refused to name 18 on-the-run killers, saying it would be "unfair" to publish the names.

Cheswold is privately run by Riverside Healthcare Ltd. A spokesman declined to comment on the escape tonight.

A request by the Daily Mail to release the identities of 18 missing prisoners was rejected by the Ministry of Justice (MoJ) - without considering whether it would be in the public interest to release the information.

In response to the Mail's request, which was made under the Freedom of Information Act, a spokeswoman for the National Offender Management Service's Security Group confirmed today the department holds the information but it is exempt from disclosure.

She said the department is "not obliged" to provide information that would contravene the Data Protection Act, adding "for example, if disclosure is unfair".

This means the department does not have to consider "whether or not it would be in the public interest" to release the information.

The fact that 18 prisoners have absconded from custody since May 2010 and have not returned to custody was originally released in a parliamentary answer given to shadow justice secretary Sadiq Khan on April 1 by Prisons Minister Jeremy Wright.

The decision not to release the names comes after a series of embarrassing escapes by inmates of low-security jails in recent weeks.

The most high-profile was Michael Wheatley - known as the Skull Cracker - who absconded from Standford Hill open prison on the Isle of Sheppey in Kent while on temporary release, during which time he is alleged to have robbed a bank in Surrey.

He will appear at Guildford Crown Court on May 29 charged with robbery, possession of an imitation firearm and being unlawfully at large.

Convicted robber John Arnold, 30, remains at large after escaping from Thorn Cross open prison in Warrington on Tuesday.

Government sources said Justice Secretary Chris Grayling was frustrated with the decision, which was taken without his knowledge.

Mr Grayling has now instructed officials to go through the list and see where possible names of the on-the-run criminals can be published, it is understood.

Identities will only remain withheld if there is a serious risk of jeopardising an ongoing police investigation by releasing them, the source added.

Mr Khan said: "The public are fed up of this Government's failings.

"Chris Grayling can't keep throwing his hands in the air at disasters that happen on his watch as if they're nothing to do with him.

"There's been the disastrous tagging of criminals and court translators contracts, prison riots and the mess at G4S-run Oakwood Prison, a collapsed serious fraud trial caused by his legal aid changes, day after day of prisoner absconds and now this.

"He needs to face the music, accept responsibility for what happens in the department he claims to run, instead of dodging the blame."