One rogue 19-year-old is a liable father to 13 kids to different mums.
A source has confirmed the man is named on the birth certificates of 13 children, and is liable to pay child support for them.
Figures released by the Inland Revenue Department show 943 teenage fathers were liable to pay child support at the end of last year. Some were just 15 years old, and already liable for two children.
A study for Inland Revenue estimates the "average" cost of raising a child to the age of 18 as $250,000. It does not count stay-at-home parents' loss of incomes or childcare costs. The weekly cost for a low-income parent raising a child is $150 - or $140,000 by the time the child reaches 18.
The circumstances of the mothers of the 13 children are unknown, but any of them who are on the domestic purpose benefit are entitled to upward of $293 a week, as well as an accommodation supplement and other top-ups.
So benefits to support those 13 babies could be costing the taxpayer more than $200,000 a year.
Dame Lesley Max, who works with children, young people and families through the Great Potentials Foundation, was shocked to hear the figure.
"My chief concern here is for the children of these boys. The more complex a society is, the more mature a parent needs to be.
"Where a pregnancy occurs between teenagers, and where there is excellent parental support and a responsible attitude on the part of the teenagers, there can be a good outcome. But that's not what we're talking about here.
"We're talking about a pathway to lifelong poverty, to deprivation for children, both materially and in parental care," she said. "In our work, we've become only too aware of older men who have tom-catted their way through life, leaving damaged children with damaged mothers. But what we're now learning about the same behaviour in teenagers is a new shock."
Brendon Smith, of Father and Child, said most young fathers wanted to be involved in their children's lives but did not get the same State support as young mums.
"Young dads need to be included and welcomed into parenting groups and antenatal classes. Midwives need to include the dads in appointments.
"Becoming a father can be the motivation they need to clean up their lives and this can happen if they get the right support," he said.
Nick Grace is a young dad with two children to two women.
He was 18 when he learned his girlfriend was pregnant.
"I was over the moon," he said. "At the time I was out with my mates drinking and I was really excited. Once I sobered up I was a bit scared but excited for the fact I was going to be a father."
The difference is that Grace, now 25, is caring fulltime for his older daughter.
"I had my girl living with me since she was one and she's now 6," he said. "I was scared about having her fulltime. I actually grew up quite fast. I was still wanting to go out with my mates but soon realised I couldn't."
He separated from the mother, who now lives in Wellington.
"She has her at school holidays and we alternate Christmas and birthdays," he said. "I also have a 1-year-old but she lives with her mother."
Grace, who works as a mentor for Thrive Teen Parent Support Trust, said being a young parent was difficult financially.
"We work it out. Communications is the key," he said. "We just have to be transparent with each other and it's all about the children at the end of the day."
How responsible are our teenagers?
Do you know of any such prolific young dads? How does it feel as a young mum to discover that the teenage father of your new baby will never be able to fulfill his child support liabilities? Email us: firstname.lastname@example.org