Dr Lesley Carroll

In the past decade, more than 1,000 prisoners have been put in care and supervision units (CSUS) in jails for that period of time.

In 2010, some 587 prisoners were held in a CSU, 25 of them for more than 15 days. Last year, however, that figure had more than doubled to 1,340 prisoners, with 195 of them having been held for more than 15 days in isolation.

Prisoner Ombudsman Dr Lesley Carroll said that being put in a CSU did not necessarily mean being put in solitary confinement.

Dr Carroll said: “I recognise that CSUS are required to be carefully managed so as to ensure that there is engagement with officers, healthcare and governors throughout each day (and that) exercise time is provided and reading or other materials during time in the CSU.

“When each of these elements of policy and practice are carried out to the required standards, the CSU cannot be considered to be solitary confinement, as defined by the Mandela Rules.

“I have visited units on many occasions. Prisoners are there for a variety of reasons, ranging from their own safety and the safety of others to reasons of discipline and good order.”

The Prison Service said: “CSUS play an important role in each of our prisons as places where individuals can be kept apart from the general population in the interest of good order and discipline or for their own protection.

“An individual may be placed in the CSU as a result of breaching prison rules, including engaging in harmful behaviours, violence, disruptive, aggressive or anti-social behaviour, and drug seeking, taking or trafficking.

“Every case is considered on an individual basis and there is a stringent and transparent process to manage and review. Prisoners are only held in the CSU for such a time as is considered to be absolutely necessary and the initial period of restriction will not exceed 72 hours.

“All cases are reviewed weekly through the CSU manager’s assessment, which allows for any application to be ended if the specific circumstances change.”