All prisoners who request special protection will be moved to a single-occupancy cell for 24 hours following a recommendation from the team investigating the death of Gary Douch in Mountjoy prison on Monday night.
Michael Mellett was appointed by Minister for Justice, Equality and Law Reform Michael McDowell to investigate the death. Mr Mellett is working with the Independent Monitoring Commission.
Today he issued a an interim recommendation that where a prisoner seeks special protection and the Prisons Authorities accept that there may be some substance to the allegation, "the threatened prisoner should be removed to a single-occupancy cell or room for at least 24 hours".
Mr McDowell said he has directed that the Irish Prison Service implement this recommendation immediately.
But this evening Eugene Dennehy, deputy general secretary of the Prison Officers Association (POA), claimed the State's prisons have no room to isolate inmates facing death threats.
Mr Dennehy said: "The problem is, as has been outlined, that there are no single cells available. So how are the prison staff to carry this instruction," he said.
Mr Dennehy said the POA had tonight sent a letter to the minister advising him they supported the proposed 24 hour single-cell lock up, but that it was unworkable.
Douch (21) from Tallaght, Dublin, was severely beaten and strangled - allegedly by a 23-year-old man from Coolock.
The suspect has been questioned by gardaí after the killing and had recently spent time in the Central Mental Hospital.
Douch had expressed concern for his safety on the day before he was killed, and prison authorities transferred him to the holding cell for his own safety. There were six other inmates in the holding cell.
