Grandparents described as "the perfect family" have been banned from taking in their baby grand-daughter because they believe in smacking.
Brian and Hannah Johnson, of Tauranga, have two adult children of their own, have been Child, Youth and Family caregivers for a niece for 13 years, and have brought up an 8-year-old grandson since he was a baby.
But CYF has refused to let them take in their grandson's 21-month-old half-sister because they told CYF they smacked their grandson occasionally as "a last resort".
Mrs Johnson, 57, said a CYF social worker told her last week: "We were the perfect family, perfect grandparents, if it wasn't for that little thing and that was smacking.
"I feel like our name has been tainted now," Mrs Johnson said.
"I went out of my way, I worked for them for this long time unpaid, I have done it out of the kindness of my heart to be of service to them, I have been up to the CYF office so many times it's not funny.
I don't feel like I've been fairly treated."
She sought help from Ngai Te Rangi social services, the Maori Party, the Social Development Ministry, Social Development Minister Paula Bennett and finally the Family First lobby group.
Family First director Bob McCoskrie said the Johnsons' experience, and six other new cases he has documented, showed "good families" were being penalised by the 2007 law change that banned parents from using force against children for "correction".
"Not only are police resources being wasted on investigating 'smacking' allegations, but CYF is ignoring the intent of the law and is removing children from good homes where the parents may use a smack," he said.
The Johnsons' daughter, who is now 27, was still living at home with them when she had her first child eight years ago.
She moved in with the baby's father soon afterwards, but suffered severe post-natal depression so her parents took the baby boy back until she was better.
"She and her partner broke up. He's in Australia now. So I've had him [the boy] ever since," Mrs Johnson said.
The daughter had a second son, to a different partner, five years ago. CYF removed that baby because of domestic violence and gave him to the baby's other grandmother.
A baby girl born 21 months ago, with a third partner, was also removed by CYF because of "domestics". The Johnsons were reluctant to take her but eventually offered to do so rather than leave her in non-family foster care.
CYF officials were keen at first to give her to them, but changed their minds after interviewing the 8-year-old boy at his school and re-interviewing Mr and Mrs Johnson.
"They asked [the boy], 'What are the things you don't like?' He said, 'Smacking and vegetables'," Mrs Johnson said.
"When they had the interview with my husband, he actually admitted to smacking, but it was not to say that we did it all the time. It was a last resort.
"It's usually a smack with the hand, but as a last resort we use a wooden spoon."
CYF operations general manager Marama Edwards said the agency "has a no hitting or smacking policy for caregivers".
"This couple's choice of disciplining methods is the reason we declined their application to be CYF family caregivers for this child," she said.
Parents can use reasonable force to: Prevent harm to the child or others.
Stop the child committing a criminal offence.
Stop offensive or disruptive behaviour.
For "the normal daily tasks that are incidental to good care and parenting".
It is illegal to use force for "correction".