by Chris Kelly
BBC News, Bristol
Dozens of inmates walk out of the open prison each year
Pressure to transfer "less trustworthy" prisoners to an open jail near Bristol has led to more than one inmate a week walking out of the facility.
Freedom of Information Act figures obtained by the BBC News website show that 66 prisoners walked out of Leyhill Prison in the 2005/06 financial year.
The figure was almost double that a year before with 114 walking out.
A Prison Service statement blamed the rise - up from just 33 in 2002 - on "population pressures".
The statement went on to add the problem was down to the need to "identify more prisoners for transfer to open conditions".
"Pressures on places meant that the whole prison estate had to be used at 95% capacity.
"Prisoners were rigorously risk assessed, particularly in regard to the risk they presented to the public.
"But inevitably some short term prisoners who proved less trustworthy were placed in open conditions."
Leyhill Prison governor Richard Booty said: "Public protection is paramount and prisoners at Leyhill are returned to closed conditions when our risk assessments indicate likely non-compliance."
Northavon MP Steve Webb, who has criticised the prison authorities over the numbers absconding in the past, has called for more checks on inmates before they are transferred to Leyhill.
"People going to open prisons should be properly vetted for the risk of walking out and their risk of reoffending.
"If the prison system is so full that too many people are going to Leyhill then the public has a right to be concerned."
One resident, who lives near the prison, said the numbers absconding was like the "charge of the light brigade".
"They've got their white bags with their clothes for changing. They're picked up by cars and they're gone.
"I have complained about it several times to Leyhill. They don't seem to be interested and tell you to go away."
Another said she was surprised by the number of inmates walking out of the jail.
"That number is quite astounding, really. We were aware there were some absconding because we often see helicopters flying over our garden."