A grandmother who repeatedly raised concerns with Child Youth and Family about her granddaughter says the agency ignored some obvious red flags.
Dawn Bell, who lives in Auckland, is caring for her 17-year-old granddaughter, but is critical of CYF's failure to act when she raised concerns.
Her son split from his wife when their two girls were aged four and five, and about three years later, the mother sought, and won, full custody in the Family Court.
Ms Bell said it was clear that the mother was not coping and nothing was done, despite her raising concerns with CYF and police that the younger daughter was being physically abused.
She said it was not until the mother poured hot water over her daughter, causing second degree burns, that agencies got involved.
"One night the youngest then is 13 and she rings up hysterical at about 11 o'clock at night. And I finally get her to calm down and she says, 'Mum has thrown hot water over my back'.
"So we went over there and there was a probably about a six inch blister and a second degree burn on her back and we took her to Starship and that got action."
Subsequent investigations uncovered what the grandparents had long suspected and had tried several times to talk to Child Youth and Family about, that their granddaughter was being physically abused.
"What we discovered is that her mother was hitting her hard to get bruises, two or three times a week. She was grabbing her by her hair and pulling her down to the ground, frequently. And when she came to us her scalp was encrusted, it took months to settle."
A broken arm, which the granddaughter had insisted was the result of a fall, was inflicted by her mother's boyfriend, now husband.
"He had twisted her arm so that it broke. And we didn't know this was happening. We didn't know to get her out of it," she said.
"My heart goes out to CYFs because it's a tough job. They're overwhelmed and they are poorly run. It's one of the toughest jobs you can get in social work.
"But we had raised a red flag, on more than one occasion."
"It's two-fold my concerns. One is that adversarial court system that disadvantaged the girls. And the other one is when we raised the red flag it seemed like nothing was done," she said.
Minister for Children Anne Tolley said the agency was in a difficult position, as it faced criticism if it intervened and also if it failed to.
She said the new Ministry for Vulnerable Children, which launches in April, will take four to five years to bed in and will cover a much wider range of work with vulnerable children and their families.