More than 20 convicted murderers absconded from Leyhill Open Prison near Bristol in the last five years, according to new figures.
Dozens of inmates walk out of the open prison each year
The information came to light after Yeovil MP David Laws tabled parliamentary questions to Home Office minister Gerry Sutcliffe.
Six rapists were also among those who have absconded from Leyhill since 1999.
The figures follow a BBC investigation which showed more than 300 inmates absconded in the past three years.
Mr Sutcliffe said: "As soon as a prisoner is found to have absconded from an open prison the local police are informed immediately.
"The prisoner's security category is reviewed when the prisoner is recaptured and returned to an appropriate closed prison."
The Prison Service, in a statement to the BBC, said the numbers of people absconding was down to "less trustworthy" inmates being transferred to Leyhill.
"Pressures on places meant that the whole prison estate had to be used at 95% capacity.
Murder - 22
Rape - 6
Robbery - 41
Various drugs - 19
Burglary - 103
Assault - 4
"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."
Northavon MP Steve Webb said the public should be concerned if proper checks are not carried out.
"People going to open prisons should be properly vetted for the risk of walking out and their risk of re-offending," he said.
"If the prison system is so full that too many people are going to Leyhill then the public has a right to be concerned."
The Home Office figures also show that 41 inmates convicted of robbery absconded, 19 convicted of various drugs offences and 103 serving time for burglary.