A scathing report has slammed New Zealand for its overuse of solitary confinement - found to be four times higher than in English prisons and in breach of international standards.
Children, disabled people and the mentally unwell were also isolated at high rates, and in conditions considered "stark" and "impoverished", according to Dr Sharon Shalev, an international human rights expert.
Dr Shalev was funded by the United Nations to visit New Zealand last year at the request of the Human Rights Commission, due to ongoing concerns about the use of solitary confinement here, including the case of Ashley Peacock, who was isolated in a psychiatric ward for more than five years.
Her report highlights a raft of issues, the most serious being the continued use of seclusion on mentally unwell prisoners; and the solitary confinement of children - both against international standards.
It again raises concerns about two other long-term patients, both in isolation for six years, a situation already repeatedly covered by the Ombudsman's torture inspectors in their annual torture reports.
Dr Shalev visited 17 sites including prisons, hospitals, children's homes and police cells but not schools or rest homes. Data was provided to her by the organisations, although not all had complete records.
Corrections' data showed there were 16,370 recorded instances of segregation in New Zealand in the year to Nov 2016, four times that of England and Wales. Maori and women were both overrepresented.
Site visits found barren conditions in most instances, with some segregation units lacking access to water and fresh air.
It also noted multiple issues in police cells, including insufficient blankets and pillows, no clear minimum entitlements for showers, exercise, phone calls and other things, and a lack of privacy.
During a visit to a government-run care and protection residence, Dr Shalev was surprised to find children being held in "secure care" units which looked identical to a prison segregation cell, where up to 20 children had been isolated in just six months.
"The use of confinement on children was very, very disturbing," she said. "Children should not be locked in a barren cell for hours on end. Especially those children, they should be treated with extra care."
At both the care residence and a youth justice facility, Dr Shalev found a call bell system in the segregation room wasn't working, meaning children had to bang on the door to get staff attention if something went wrong.
"International human rights law and principles of good practice call for a complete prohibition on the use of solitary confinement with children," she said. "This is inappropriate."
Dr Shalev also highlighted the small but persistent number of "chronic" cases where solitary confinement and restraint were used for prolonged time - such as Ashley's case.
It was concerning to see very little thinking about new solutions for those people, she said.
"There was almost an apathy. There was an assumption that this is how things are done and this is how they will continue to be. No one was thinking outside the box," Dr Shalev said.
"I should acknowledge these organisations do deal with complex individuals but overall on balance between individual need and staff needs - and fear- it was always staff safety or perceived safety that seemed to take precedence."
Seclusion is considered potentially harmful - particularly to vulnerable people - due to its "toxic" combination of social isolation; a monotonous physical environment and institutional control. As such, it is monitored under strict human rights laws.
Chief Human Rights Commissioner David Rutherford said while the report made for sobering reading, the focus should now be on how the recommendations can be used to reduce the occurrence of seclusion and restraint in New Zealand.
"Many of these concerns have been raised by other monitoring agencies in the past. For example, the Children's Commissioner has repeatedly raised concerns about the holding of young people in police cells - this report highlights the grim reality that they can face and it is time for urgent action to be taken.
Children's Commissioner Andrew Becroft said he hoped the report would give the Government the impetus it needed to change the law on remanding children into police cells.
"It's bad enough that adults are kept in conditions like these but for a child, the effects of even a short time in solitary confinement can be extremely damaging," Becroft said.
"The whole report is a sobering wake up call. We are out of line. We are in flat out contravention of our human rights obligations and we can't afford to play with fire when it comes to keeping children in solitary confinement."
Oranga Tamariki (formerly Child, Youth and Family) said it was working to address the issues identified.
"Simple things, like refreshing the spaces and making sure the infrastructure is sound - such as the call bell system - is under way," it said.
It would also be developing community-based solutions for young people on remand, in an attempt to minimise those in residential care.
Corrections' Chief Custodial Officer Neil Beales said the department broadly agreed with the report, although parts were "one dimensional".
He said some improvement initiatives were under way including a review of "at risk" prisoners and a strategic plan to provide a greater level of mental health, alcohol and drug support to prisoners.
"In years gone by the management of mentally unwell patients has gone so far - but it can go further in terms of making things more therapeutic," he said.
However, that would not compromise either staff nor inmate safety.