A man has been arrested following the death of an inmate at Cloverhill Prison.
A man in his late 30s was treated by emergency services following an incident at the jail in the early hours of Saturday but pronounced dead at the scene a short time later.
The post mortem was completed by State Pathologist Dr Margaret Bolster, however the results will not be released for operational reasons, a garda spokesman said.
On Sunday morning, a man in his 50s was arrested at Cloverhill Prison on suspicion of murder.
He is being detained at Clondalkin Garda Station under section four of the Criminal Justice Act 1984.