Gardaí are continuing to investigate the death of a 24-year-old prisoner at Mountjoy Prison, Dublin, from stab wounds received in an altercation with a fellow inmate on Monday evening.
However, while officers are following a definite line of inquiry, no formal arrest had been made by yesterday evening. A separate Prison Service investigation into the attack is also continuing.
Derek Glennon, who was originally serving a five-year sentence for manslaughter, died just before 6pm after a dispute arose between two inmates.
A knife was produced and Mr Glennon received serious stab wounds to the chest area. He was removed to the nearby Mater hospital, where he later died.
The other man involved was apprehended. It is understood that he was questioned by investigating officers yesterday.
In response to the death, the Prison Officers Association (POA) met the director of the Prison Service, Brian Purcell, yesterday evening to discuss their concerns. POA president Jim Mitchell told The Irish Times that despite previous commitments that the population of Mountjoy Prison would not rise above 480, there were 568 inmates there.
He also expressed surprise at what he described as "somewhat defeatist" comments by Mr Purcell in relation to the attack.
On RTÉ radio yesterday, Mr Purcell said the attack appeared to have come "straight out of the blue. There was no indication of anything like this happening.
"The staff in the prison reacted immediately and were on the scene straight away. And they did everything possible but unfortunately this was too late," he said.
"I think what you have to remember is that there's a balance to be drawn between the human rights of prisoners and the risks associated with having people together in a prison setting.
"And short of locking prisoners up for 24 hours a day, it's very difficult to prevent with complete certainty violent incidents occurring from time to time in the prison."
Mr Purcell confirmed he is due to receive a report in the coming days into how a prisoner was released from Mountjoy prison by mistake last week. Mark Kenny (35), who was serving a six-year sentence for robbery, was released instead of another prisoner with the same name. "It looks like this was perhaps an error," Mr Purcell told RTÉ.
Mr Mitchell claimed Mr Purcell's attitude to Mr Glennon's death would do little to enhance the security of prisons. "One of the issues which is definitely contributing to the problem in our prisons is overcrowding, and this particularly applies to Mountjoy," he said.
Mr Glennon, Stanaway Road, Crumlin, Dublin escaped from custody in October 2005 while serving a sentence for manslaughter. He was apprehended and jailed for five years at Dublin Circuit Criminal Court.
Glennon had been jailed in January 2004 after he pleaded guilty to the unlawful killing of Neil King at Davitt Road on December 16th, 2002. He killed the cyclist when he was trying to avoid gardaí after being caught driving a stolen car.
While serving his sentence, Glennon was escorted to St James's Hospital by three prison officers.
He was outside smoking when a man approached and pointed a gun at the officer to whom he was handcuffed. The officer was threatened and Glennon was released.