Published Monday, 15 October 2012
An investigation has begun into the death. (© UTV)
Efforts to revive 28-year-old Michael McDonagh proved unsuccessful after he was found in a collapsed state in his cell in the early hours of Monday.
The Northern Ireland Prison Service said he was pronounced dead at 1.40am.
Investigations are ongoing and the PSNI, Coroner and Prisoner Ombudsman - as well as Mr McDonagh's family - have been notified.
Prison Service Director General Sue McAllister said: "I would extend my sympathy and that of the Northern Ireland Prison Service to the family of Mr McDonagh.
"This is a tragedy and my thoughts are with them at this difficult time."
Tom Elliott, Ulster Unionist Justice spokesperson, said he was "deeply concerned" to learn that a remand prisoner had died in custody.
"Obviously this incident is subject to due process with the PSNI, Coroner and Prisoner Ombudsman having all been informed. The Prisoner Ombudsman will carry out a full investigation as with all deaths in custody."
Mr Elliott said he will be raising the issue with the Justice Minister David Ford at the next available opportunity.