The Children's Commissioner is demanding to know whether police are routinely taking pictures of young people on the street nationwide.
He joins others, including Wairarapa iwi, calling for an investigation after the police in the region admitted illegally taking pictures of young Māori.
Whānau in Wairarapa described their sons walking alone in broad daylight when police approached and insisted they take their picture before letting them go on their way.
Children's Commissioner Andrew Becroft said what was being described was shocking.
"This is not constructive or responsible policing," he said.
"This sort of practice is entirely corrosive and unhelpful. And without a valid arrest it would be hard to see how there'd be any basis for taking photographs, and it would be very hard to see how any child or young person could give any meaningful consent to such a process.
"I think it's just plain wrong."
After enquiries from RNZ, Wairarapa police revealed that an August review found three photographs, all of young Māori, contravened legislation and had since been destroyed.
Police said the youth matched descriptions of suspects identified in a series of car thefts in the middle of the year.
They said all other photographs of young people at that time were taken lawfully.
But Wellington police district commander Corrie Parnell was surprised to be told by RNZ of multiple reports describing a pattern of police photographing tamariki in the region going back at least two years.
Judge Becroft wants answers from the Youth Policing division and a nationwide investigation.
"I'll be letting the [Police] Commissioner and the [Police] Minister know of our concerns.
"I think it's in everybody's interests that this is followed up and it's clearly established one way or the other if this is just a local policy where over-zealous police officers have got it wrong, or whether it's something of a national policy.
"And I'd like to know for sure what police are being instructed as to what they can and cannot do."
Community Law chief executive Sue Moroney agreed an urgent review was needed.
"I think what New Zealanders need is certainty about how widespread this practice has been - how has this particular section of this Act been used or potentially misused throughout the entire country.
"And have certainty that the police are actually acting within the law right across the country."
She said community law member YouthLaw Aotearoa would help young people make a complaint if they believed they had been illegally photographed.
"They would be keen to support any family or person who has actually been subjected to this practice to consider taking a complaint forward to the Independent Police Complaints Authority, if there are the grounds for that."
Police concede that more people could have been improperly photographed and want anyone concerned their rights had been breached to come forward.
Privacy Commissioner John Edwards said in a statement he had sought more information from police about the matter.
He says new privacy laws that came into force this month make even more explicit the Police's obligation to collect young peoples' personal information in a lawful, fair and unintrusive way.
Police have cited a section of the Oranga Tamariki Act as the legal basis for other photographs of youths it said were taken lawfully.
Barrister and YouthLaw Aotearoa chair Simon Judd told Morning Report this section referred to arrests and did not give police the power to photograph people in the street.
RNZ
