Social Development Minister Anne Tolley has ordered a full review of how Child Youth and Family handled the case of a 3-year-old girl.
The agency has been criticised by a Family Court judge, who said it had put the child at unacceptable risk by providing misleading information about her father.
RNZ revealed Child, Youth and Family (CYF) had repeatedly - and wrongly - told the court the girl's father was violent. The incorrect information added a five-month delay to the man gaining the care of his daughter, and he was now suing the agency.
Ms Tolley said CYF did not handle the case well at all, and gave her, the child's father and the Family Court misleading information.
"It is really disturbing when they gave me advice consistently, and I'm a bit cross about that.
"It's always very difficult for the minister to interfere when something's in front of the Family Court.
"But I have to be able to rely on their assurances that they've done a full investigation."
Ms Tolley said the outcome of the review, to be carried out by the Chief Social Worker, would be considered, alongside work that was looking at creating an independent authority to investigate complaints and failures by CYF.
The young girl had been living with her mother, who was taking drugs and in an abusive relationship with a violent boyfriend.
In his decision, Judge Anthony Walsh dismissed the CYF reports about the father as unsubstantiated and unverified.
CYF has apologised, but the father was now suing the agency to recoup more than $10,000 in legal costs and pay for therapy for his daughter.