Police are still searching for a fourth prisoner who has gone missing from Prescoed open jail in Monmouthshire.
Locals are opposed to high-risk prisoners being held at Prescoed
Philip Parfitt, 44, who was convicted of grievous bodily harm, failed to return from home leave on Thursday.
Last weekend three inmates, including two child rapists, absconded from the jail but are now back in custody
The Home Office said public protection was at the heart of its work and the circumstances surrounding this incident would be "thoroughly investigated".
Parfitt was sentenced to four-and-a-half years for grievous bodily harm at Cardiff Crown Court in 2004.
He had been allowed a week's home leave, a usual practice for prisoners nearing the end of the sentence, but failed to return.
Local councillors said they were "shocked" and have called for urgent talks with the Home Office.
Usk councillor Alec Leathwood said: "We weren't told that there was a fourth absconding from Prescoed, so that's worrying.
"[But] we're not too worried, given that he's a more minor offender than the others, but none the less, you have to be concerned where four prisoners have gone within a week.
"But it is an open prison, and there's no security there whatsoever, so prisoners can walk away whenever they want, which is why we don't want sex offenders there."
News of Parfitt's disappearance comes just days after two child rapists, John Elms and Martin Aspinall, both serving life and a burglar, Marc Barnett, absconded from Prescoed.
Aspinall (left) and Elms have been charged with escaping custody
It has since emerged that one of them had walked out of another prison five years earlier.
Usk council is pressing for an urgent meeting with Home Secretary John Reid and for a review of the sex offenders programme at the jail.
William Graham, Conservative AM for South Wales East and a former magistrate, said open prisons were a valid element of the criminal justice system but said the Home Office was selecting the "wrong people" to send to Prescoed.
He said: "We should not have people convicted of serious paedophile offences, where we know that the rate of re-conviction is extremely high.
"We do not want another person who absconds from Prescoed prison because they have been wrongly sent there, that's where the Home Office is at fault."
A widescale search was mounted for Aspinall, 46, and Elms, 34, after they had absconded last Friday night.
Elms was jailed in 1996 for raping a teenage girl and Aspinall was jailed in 1992 for raping a minor and kidnap.
They were at large for 48 hours, and were recaptured on Sunday five miles from Prescoed.
Burglar Marc Barnett absconded on Saturday and was recaptured on Sunday, a few hours after the paedophiles' rearrest.
A Prison Service spokeswoman said of Parfitt's absconding: "An HMP Prescoed prisoner has failed to return to HMP Prescoed from home leave. This is now an operational matter for the police."
In response to a parliamentary question on 25 July, the Home Office released figures which showed there were nine abscondings from Prescoed during 2005-06, 19 the previous year and 35 in 2003-04.