Up to one in four prisoners in Mountjoy are requesting single cells because gang culture is such a threat in the jail.
A 2016 report by the Mountjoy Prison Visiting Committeee says gang culture is resulting in a rising need for protection and the lack of a drug-free environment.
The Irish Examiner details how it's posing a challenge to staff who are trying to balance the security threat with out-of-cell time in workshops and recreation.
The problem is also hindering the rehabilitation of criminals.
Meanwhile the Cloverhill Visiting Committee also said gang culture is continuing to pose a serious problem.
While the Dochas Women's Prison committee said drugs are fuelling aggressive and bullying behaviour.