A review into the use of segregation and force in New Zealand prisons is underway, as Corrections continues to face pressure over its treatment of inmates.
The Office of the Inspectorate says it has launched the review to look at whether Corrections practices are consistent with the law and policies and procedures.
The review is one of many sparked by the treatment of three inmates at Auckland Women's Prison.
RNZ revealed last year that Mihi Bassett, Karma Cripps and another woman were gassed in their cells with pepper spray, forced to lie face down in their cells before being fed and were unlawfully detained for months in a segregation unit.
Bassett's mental health declined and she attempted to kill herself in her cell. In the minutes after the suicide attempt, she was placed in handcuffs and threatened with pepper spray. She was returned to segregation the next day.
Chief Inspector Janis Adair said the latest review was being undertaken to see if practices needed to be updated.
"If there are lessons to be learnt or practices to be updated, I want these to be considered at the earliest opportunity," she said.
Adair had committed a dedicated team of inspectors to the review to ensure it was completed in a robust and timely manner.
The review will focus on how Corrections uses directed segregation and force as part of its approach to managing prisoners, and whether this is consistent with the Corrections Act, Corrections Regulations, policies and procedures.
Corrections is only supposed to segregate prisoners to protect the security or order of the prison, to maintain the safety of another person or in order to assess or ensure the prisoner's physical or mental health.
Bassett and Cripps were kept in segregation for four months.
Earlier this month the Inspectorate, which is part of the Department of Corrections but functions independently, released three reports into management of women in jails, including one into the treatment of Bassett, Cripps and a third woman at Auckland Women's Prison.
It found a "catalogue of failures" and said "not only did the system fail the wāhine, it also failed to support the staff who were charged with managing them".
The Inspector recommended Corrections "undertakes at pace, a robust review, rethink and redesign of the way in which wāhine across the prison network are managed".
Earlier this month an Oxford criminologist said she was "outraged" at the way women were treated in New Zealand prisons.
Dr Sharon Shalev, an expert on America's supermax prisons, was asked to review New Zealand's three women's prisons by the Human Rights Commission.
She told RNZ that what she found was "extremely troubling".