A 22-YEAR-OLD male prisoner has died at Maghaberry Prison in County Antrim.
The inmate was found dead on Thursday morning, the Northern Ireland Prison Service (NIPS) said in a statement.
No details about the young man or the circumstances surrounding his death have been revealed.
His next of kin have been informed along with the PSNI, Coroner and Prisoner Ombudsman.
NIPS director general, Ronnie Armour, said: "On behalf of the Northern Ireland Prison Service, I would like to extend my sympathy to the family of the prisoner.
"My thoughts are with them at this difficult time."
Sinn Féin Justice spokesman Raymond McCartney said he was "concerned" to learn of the tragedy.
"I extend my condolences to the family and friends of this prisoner and my thoughts are with them at this difficult time," he said.
"It is important that the relevant authorities carry out a full and thorough investigation into this death."