A privacy breach by Child Youth and Family has resulted in the department taking legal action, claiming a woman was trying to blackmail them after it accidentally sent her somebody else's private information.
In a statement, CYF head Bernadine Mackenzie said the department had mistakenly sent a Family Court document to another person, who was refusing to return or destroy it.
"She is demanding that we return one of her children to her care in exchange for the document," Ms Mackenzie alleged.
Social Development Minister Paula Bennett said the mistake was disappointing and would be investigated, but appeared to be human error. The document was mistakenly sent with other material to the woman a few days ago. CYF realised their mistake and tried to get the document back, but the woman refused and allegedly said she would go to the media if the department did not return her child.
"It was personal information on a young person that certainly should not have been passed to someone else.
A mistake has been made by the Department.
"We can't overlook that and they have fronted up and apologised for it. But someone can't try and blackmail the department to try to get back their child, when there are obviously reasons for that."
Ms Mackenzie said the department had served the woman with an order from the Family Court to prevent publication, and applied to the courts for the return of the document.
"Any institution that holds private information needs to be accountable when there is a breach. However, there is also a responsibility that extends to the person who receives private information in error."
Ms Mackenzie conceded it was the department's mistake in the first place, and it had apologised to the family whose information was involved.
"A mistake has occurred and I'm sorry that our actions have seen a family's private information passed to a third party. It should never have happened, and we've apologised to the family for this."