Investigating the use of seclusion rooms in New Zealand schools is at the top of his priority list, the Chief Ombudsman says.
The office is investigating after receiving complaints about at least two schools confining children, including some with autism, in small rooms.
Last week it emerged that Miramar Central School in Wellington had been confining children in a small dim room in response to behaviour such as hitting, biting, kicking, choking and slapping.
In a separate case, involving Invercargill's Ruru Specialist School, a nine-year-old autistic boy was restrained and transported by van to a seclusion room.
The incident happened in 2011, but it was three years before his parents were told.
The boy's parents wrote to Education Minister Hekia Parata in May 2015, concerned an investigation was leading nowhere.
A report commissioned by the Ministry of Education into the confinement of the boy found that, although not illegal, the use of such rooms in special education schools was common practice.
The report, written by consultant and psychologist Terri Johnstone, who also conducted the investigation at Miramar Central School, found the room was dark and grimy and not pleasant.
A police investigation is ongoing.
'We won't let this just gather dust'
Chief Ombudsman Judge Peter Boshier told Checkpoint with John Campbell he took these cases seriously.
"A couple of seclusion incidents have come our way, of a quite high-profile nature, recently. And we feel that within our brief and our investigation powers these are cases that we ought to put at the real top of our priority list."
Judge Boshier said he was duty bound to investigate because of New Zealand's United Nations agreements and international reputation.
He said, under the UN obligations, detention outside of a prison or mental health unit needed to be investigated to see if it was reasonable.
"We will not mess around on this - it will have a high profile, there could be other incidents throughout the country, I don't know.
"I think it's really important for the disability community, for the education community and internationally that we're not seen to be dragging the chains... We won't let this just gather dust."
Meanwhile, the Ministry of Education said it was acting on complaints about the use of seclusion rooms.
Its head of special education, David Wales, said, among the country's roughly 2500 schools, there had been a handful of complaints relating to schools using seclusion.
Mr Wales said schools were due to be educated on the use of seclusion and restraint this term.