Oranga Tamariki has apologised for keeping a child in hospital because it could not find a suitable placement, describing the case as "unacceptable".
RNZ revealed today that a child spent more than nine weeks on a Waikato hospital ward.
DHB staff called for a review as the child did not require admission to hospital for any medical reason and was not unwell.
Staff at Waikato District Health Board were "extremely distressed" by the agency's treatment of the traumatised child, who expressed "feelings of abandonment".
The Minister for Children is calling for an investigation into the case and advocates say it is disturbing and outrageous - and validates calls to scrap Oranga Tamariki as a whole.
Oranga Tamariki spokeswoman Glynis Sandland confirmed the agency received a complaint from DHB staff.
She said the body did not do its best for the child.
"We are sorry for this as it was not acceptable.
"We have investigated the DHB complaint fully and apologised to the staff that were impacted by the lack of quality service provided. A meeting was also offered to explore how we can work together to provide better support for children in Oranga Tamariki care who are in hospital."
Sandland said the organisation was limited in what it could say because of privacy concerns.