Britain's wide open prisons: 130 killers are among 14,000 convicts who have escaped from low-security jails

The huge number was disclosed amid growing evidence that many contain violent offenders.

Unions claim hundreds of dangerous criminals have been transferred to open prisons to ease overcrowding at higher security jails. Some have then committed killings and armed robberies after escaping.

Almost 14,000 prisoners have gone on the run from open jails over the past ten years. These include 130 murderers.

Around 150 of those who escaped from open prisons have never returned or been brought back to jail.

The allegations, featured in BBC One's Panorama programme tonight, brought a wave of criticism.

Prison Officers' Association chief Colin Moses attacked the use of open jails for dangerous offenders.

He said: "The risk factor is massive – the risk factor to the public, the risk factor to the staff, the risk factor to other inmates. Serious offenders are absconding and then committing further violent crimes."

Tory justice spokesman Nick Herbert said he found "extraordinary" one case of an armed robber who had escaped from a secure prison only to be transferred to an open jail, from which he absconded to commit another violent robbery.

"It is unacceptable these institutions are coming under such pressure to take unsuitable prisoners," he said.

The row over the transfer of dangerous prisoners to open jails – intended for the least threatening offenders and those reaching the end of their sentences – comes amid concern over early releases and the lighter sentencing of criminals to ease prison overcrowding.

Some 24,000 prisoners, including 4,500 convicted of violent offences, have been released early since the End of Custody Licence scheme was introduced last June. There are currently a record 82,501 prisoners.

The BBC quoted a memo written by one open prison governor voicing concern over transfers of unsuitable inmates from secure jails.

It read: "The instructions coming down are that local prisons must review prisoners on shorter sentences for transfer. I have raised my concerns that this will mean an inevitable rise in absconds.

"Ministers have been briefed to this effect and are apparently happy to take the risk."

At least one murderer has escaped from an open prison to kill again, Panorama alleged.

It cited the case of Roderick McDonald, a prisoner serving life for the murder of his wife. He was moved to Scotland's Castle Huntly open prison in 2005 and absconded soon afterwards after being refused parole.

McDonald lived secretly in Blackpool for two years, where, the programme said, he carried out a violent rape on another man.

He then moved to London to avoid police attention, where he stabbed and strangled a Brazilian immigrant, Junior Pariz, in a hotel room.

McDonald hanged himself in a cell at Brixton prison while awaiting trial for the murder of Mr Pariz.

The programme also raised the case of armed robber Richard Macdonald, who escaped from the closed Mount prison in Hertfordshire in 1995.

Sentenced to another term, of eight years, in 2003, he absconded from Spring Hill open prison in Buckinghamshire in 2006 and then again later that year from Ford open prison in West Sussex.

The following year Macdonald used a butcher's knife in a robbery in London during which he and an accomplice stole £8,000.

He was later given an indeterminate sentence for the crime.

Harry Fletcher, of the National Association of Probation Officers, told the programme: "I have certainly been worried for 15 to 18 months that individuals are being transferred into open jails in England and Wales who pose a risk to the public."

A statement from Justice Secretary Jack Straw said: "By sending more low-risk short sentence prisoners to open prisons we are able to free up places in closed prisons where pressure on places is greatest.

"These measures exclude any short sentence prisoner who has even been convicted of a sexual offence, is currently serving a sentence for a violent offence, or who is facing deportation."

He added all prisoners in open jails had been "rigorously risk assessed" and numbers absconding were at the lowest level for ten years.