A 13-year-old was branded with a swastika tattoo while in the care of Child, Youth and Family.
Solo mother Muna Fajady, of Wellington, lost the care of son Michael in September last year, and he was sent into various CYF group homes around the region until being returned to her care this week.
While he was in a group home in Porirua about a month ago, Fajady noticed a 5-centimetre-square swastika symbol on his back.
"They put a Nazi tattoo on his back. Why they did that to my son?"
Michael said another child in care at the Porirua home had branded him with a needle and ink - believed to have belonged to the carer - while the carer was not around.
He had asked for a cross "like Jesus died on", thinking it would be temporary. He was shocked by what he saw in the mirror, and realised it was permanent when scrubbing failed to remove it.
Now he will not go swimming, or get undressed in front of others.
"I just want to get rid of it," he said. "It just makes me depressed."
CYF has offered to pay for laser treatment to remove the tattoo, but Fajady, who came to New Zealand from Iran in 2003, says she wants answers, not apologies.
She also claims that, while in care, Michael was taught to smoke by other children, and was once offered alcohol. He had been having nightmares since he returned home.
"I have concerns with how my son was treated in care. It's not just about my son. People trust this department, but they did wrong. When they took him, he got worse and worse."
She said she was unsure exactly why Michael, who had been in trouble at school for continual misbehaviour, was taken from her care. She was told at first that it was due to fears that she was hurting him, because she says she was witnessed "pulling his ear".
Eventually she was told by social workers that he was to be placed in CYF care for her safety and for that of her other son.
CYF central regional director Tania Harris confirmed "this young man did receive a tattoo", saying he asked another young person to give it to him.
"Of course, this was unfortunate," she said. "No-one would condone what happened and we wish this teenager had made a different decision. But unfortunately young people sometimes make spontaneous decisions which aren't very smart."
The agency had "taken steps to have the tattoo removed", and CYF would pay for it.
Fajady said a specialist told her it would take at least six sessions of laser treatment to remove.
Sessions cost about $110. The number of treatments needed is determined by the size of the tattoo and type of dye used.
Harris said: "In our view, it is not appropriate for young people of that age to tattoo each other. We have met with this young man's mother to discuss the incident, and have spoken to the other young people involved.
"This family home provided and continues to provide good supervision of the young people living there, but they have similar freedoms and responsibilities as other teenagers and sometimes they will make a mistake."
She would not discuss Michael's case further.
Fajady said she was not sure whether Michael would now remain in her care. She is due to meet CYF on Monday.
Corrections introduced a tattoo removal programme for inmates in 2000, before axing the service six years later.
Criminals near release could have their tattoos lasered off in a series of $110 sessions, to a maximum cost to the taxpayer of $1500 over a year.
Among those to get the treatment was John Gillies, who stabbed a policeman in 1993. He had a "Mongrel Mob Forever" tattoo lasered off his face.