United Nations Standard Minimum Rules for the Treatment of Prisoners, rules 43-45
Cell confinement and segregation are forms of solitary confinement.
Under International law, solitary confinement is prohibited if it is for more than 15 days and it must not prevent you from having contact with family. It must only be used in exceptional cases as a last resort, for as short a time as possible.
There are groups in Aotearoa New Zealand arguing for solitary confinement to be made unlawful on the grounds that it amounts to cruel, inhumane and degrading treatment.
Cell confinement is of particular because it doesn’t appear to be used in exceptional circumstances as a last resort, or for as short a time as possible.
For further information on the campaign against solitary confinement you can contact People Against Prisons Aotearoa (the address is at the back of this book).