Oranga Tamariki has been accused of returning a 4-year-old boy, who had been previously injured, to his Flaxmere household, where he was then seriously injured.
It allegedly did so without full consultation with the wider family, with some opposed to the boy's return, Newsroom reports.
The boy had been removed from his immediate family after an incident in June last year that hospitalised him in Wellington - and placed in the care of a grandmother in Auckland.
Without consultation with key family members, Oranga Tamariki returned him to his "immediate" family before Christmas, Newsroom reports.
Just over a month later he was brutally injured and remains in a serious condition in Starship Children's Hospital.
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The boy's "suspicious" injuries, including widespread bruising and a brain injury, were previously compared by Detective Inspector Mike Foster to the injuries sustained by murdered 6-year-old James Whakaruru.
Foster has said the boy suffered a sustained beating - possibly over days - at a Ramsey Cres address nearly three weeks ago.
Oranga Tamariki deputy chief executive Children & Families South, Alison McDonald, has previously told Hawke's Bay Today the boy's injuries were "extremely disturbing".
"We are continuing to work with the whānau to offer support and are working with other professionals in the Hawke's Bay," McDonald said.
"We can confirm that Oranga Tamariki has been working with this family previously, and the situation involves challenging circumstances."
The injured boy's grandfather Dion Te Ahu said the decision to return the boy to the care of his immediate family is even more distressing after what police recently told him, Newsroom reports.
"I found out last week that the investigation [into the 2019 incident] hasn't been closed and that the police recommended that while the investigation is still open they shouldn't have returned [the boy] under any means."
No one in Hastings, where the boy resided, has spoken publicly about the incident.
Police said previously the family were withholding crucial information, but have declined to comment on updates to the investigation in recent days.
Te Ahu said he's decided to speak up because he wants to correct a perception that the wider family is involved in a cover-up of the boy's latest injuries.
Te Ahu also said the boy's immediate family had been advised not to talk about the incident from "a legal perspective".
Prime Minister Jacinda Ardern has urged any silent family members who have information to come forward.
Hastings Kaumatua Des Ratima said Oranga Tamariki needed to step up and accept some of the responsibility for the tragedy.
"OT have remained silent on their role is this horrific situation," he told Newsroom.
"I'm not excusing anyone for damaging our tamariki. I am saying that this situation occurred because of poor decision-making by people and institutions which should, and must, know and do things different. I am concerned that OT through their silence have lumped total responsibility on this family."
Oranga Tamariki has been approached by Hawke's Bay Today for further comment.