A prisoner has died while in custody at Northern Ireland’s top security prison.

A number of investigations have been launched into the death of the 44-year-old man, a remand inmate at Maghaberry jail, near Lisburn, in Co Antrim.

The complex houses long-term sentenced and remand prisoners, in both separated and integrated conditions.

The Northern Ireland Prison Service (NIPS) confirmed that a prisoner died on Saturday night.

Acting prison service director general Phil Wragg said: “I would like to extend my sympathy and that of the Northern Ireland Prison Service to the family of the prisoner who has died in Maghaberry.

“My thoughts are with them at this difficult time.”

A NIPS spokesman said the man’s next of kin have been informed.

“As with standard procedure, the PSNI, Coroner and Prisoner Ombudsman have launched investigations into the death,” he added.

Prison authorities have not released any details about the man’s identity or how he died.

It is at least the fourth death at the complex since a damning official report last year branded the prison “unsafe and unstable”.

A joint assessment by HM Inspectorate of Prisons and Criminal Justice Inspection Northern Ireland (CJINI) said Maghaberry was “a prison in crisis.”

Nick Hardwick, chief inspector of prisons in England and Wales, who was part of the inspection team, said at the time he had never seen a more dangerous prison environment.

“This is one of the worst prisons I’ve ever seen and the most dangerous prison I’ve been to,” he said.

Maghaberry houses almost 1,000 prisoners, including around 50 with loyalist and republican paramilitary affiliations who are held in separated accommodation.

Dissident republicans have issued death threats against prison staff in recent years and in 2012 long-serving officer David Black was shot dead by dissidents as he drove to work.