A 38 year-old prisoner has died in Maghaberry Prison, the Northern Ireland Prison Service have confirmed.
The next of kin have been informed.
As with standard procedure, the PSNI, Coroner and Prisoner Ombudsman have launched investigations into the death.
The Head of the Prison Service, Ronnie Armour said: "I would like to extend my sympathy and that of the Northern Ireland Prison Service to the family of the man who has died in Maghaberry this morning. My thoughts are with them at this difficult time."