A murder investigation is underway after a man died following an incident in Cloverhill Prison in Dublin.
Emergency services were alerted to the incident at about 05:30 BST on Saturday, gardaí (Irish police) have said.
It is understood there was a row in a cell involving three prisoners, according to Irish broadcaster RTÉ.
The man, who was in his 40s, received treatment at the scene but was pronounced dead a short time later.
Gardaí said they are investigating all circumstances surrounding the death and the scene has been preserved for full forensic and technical examination.
The coroner has been notified and the services of the state pathologist have been requested.