The United Nations Committee against Torture has published its findings on New Zealand, highlighting its concerns about the disproportionate representation of Māori in the entire justice system.
While the committee acknowledged the efforts by the government to improve prison conditions and mental health services for those in detention, it also raised a number of persistent problems in the youth justice sector.
The UN called on the government to raise the age of criminal responsibility from 10 to 14 in line with international standards, and urged for an end to the use of physical restraints such as pepper spray, spit hoods and solitary confinement for children.
The UN was also seriously concerned that no individual had been held accountable for the numerous allegations of torture and ill-treatment of young people in institutions linked to the Royal Commission of Inquiry into state and faith-based care, and that full redress for victims had not been provided.
Chief Children's Commissioner Judge Frances Eivers was part of the New Zealand delegation of child rights advocates who attended the committee in Geneva to observe and monitor the review.
The committee was very concerned by the high number of tamariki Māori in detention facilities, she said.
"Our mokopuna who are in detention they do come from places of trauma throughout their lives, that's what has led them to be in these sorts of facilities.
"When they act out or become upset for whatever reason therapeutic models in the main are not applied in Aotearoa, they are placed in what we call secure detention... which is essentially they are placed in a cell."
Tamariki could be in solitary confinement for up to three days, Eivers said.
There needed to be a re-set of the youth justice system starting with phasing out large youth detention centres, she said.
"These facilities where mokopuna are held in detention should be therapeutic, they should be community based, they should be smaller [and] especially as we are dealing with mokopuna Māori they should be run by Māori - whether that hapū, iwi or a Māori organisation but definitely our own need to be sitting at the table and making these decisions about our own children."
Transformational change was needed but it would not happen overnight, she said.
"These things happen very slowly and that's why it's really important to keep it on the radar and to keep the kōrero going and to really work hard in showing the evidence that sits behind all of this, all of the research that shows that keeping our mokopuna in large places of detention simply criminalises them."
Many of the recommendations set out by the committee were achievable, she said.
"We can do this. We just need to take one whānau, one mokopuna at a time look at their needs, put the resource in... if we can send these mokopuna and their whānau on a pathway of rehabilitation then not only are we helping them and their whānau we are actually helping the whole of Aotearoa."