Oranga Tamariki was warned about restraints at a Christchurch care and protection residence months before it was finally closed.
The concerns are highlighted in a December 2020 report by the Office of the Children's Commissioner into Te Oranga Care and Protection Residence.
It said children and young people were still being hurt during restraints.
A quote from one young person described them as "triggering for some people".
While staff were making progress in reducing the number of incidents where force was used, young people were still reporting injuries.
Assistant Māori Children's Commissioner Glenis Philip-Barbara said the residences held people with complex needs.
"They've often come from a background that's incredibly complicated, and often traumatic," she said.
"A young person who ends up in a care and protection residence has no other option for placement."
The closure of Te Oranga was announced last month, after Newsroom published leaked footage of a young person being tackled, restrained and held in a headlock by staff.
On 1 July, Oranga Tamariki acting chief executive Sir Wira Gardiner said the decision had come after a number of serious issues had come to light in the previous week.
But the OCC report had been published in December 2020, seven months before the closure announcement by Gardiner.
It had also talked about bullying, feelings of being unsafe, staff putdowns and inappropriate comments.
Philip-Barbara said while the office was pleased action at Te Oranga had been taken, worries about care and protection residences stretch back years.
"One of the reasons that we decided to publish our monitoring reports from now on, is to ensure that there is a much more public eye on the concerns that we have."
Mentions of harmful restraints were not just isolated to the Te Oranga report.
They were also raised in a report from this year into the Epuni Care and Protection Residence in Lower Hutt.
Children and young people there thought staff were using force inappropriately, one said it was kind of like manhandling.
"We believe that all care and protection residences should close," said Philip-Barbara. "We're advocating for smaller community based places, therapeutic in focus, tailored to the specific needs of young people in their care and in some cases highly secure so that young people who present a risk to themselves and others can be appropriately cared for."
One staff member in that report said Epuni felt like a ward on a mental health unit without the environment or training to match the need.
Philip-Barbara said staff in other residences had similar concerns around training.
"We've raised this issue about staff feeling and being often under-trained and just, the risk of harm that exposes young people to," she said.
"This again has been a theme of our reports for many years."
Response from Oranga Tamariki
Oranga Tamariki could not comment specifically on Te Oranga due to ongoing investigations.
In a statement on restraints in care and protection residences spokesperson Audrey Bancroft said they should only be used in extreme circumstances.
Reasonable grounds could include self-defence, or to protect a child or young person from injury or attempted self-harm.
"Staff must use physical holds that are reasonable in the circumstances," she said.
"When it is assessed that physical holds are necessary, it must be the least restrictive form necessary, and only applied for as long as necessary to prevent an individual harming themselves or others.
"Physical force must not be used when a less intrusive form of intervention is adequate."
Bancroft said when a restraint was used, residence management would undertake a debrief with the staff involved and a review process would be carried out.
"All alleged breaches of the Oranga Tamariki code of conduct and other policies are acted on appropriately, in line with Oranga Tamariki policies and procedures," she said.
"Where an allegation relates to the actions of an Oranga Tamariki employee toward tamariki or rangatahi in our care, the type of investigation undertaken and whether the employee continues to attend work during the investigation will depend on the circumstances and potential seriousness of the issue."