A mother and her 6-month-old daughter were forced to take a DNA paternity test to avoid Oranga Tamariki "uplifting" the baby - despite the fact the man the agency believed had fathered the child was in prison at the time she was conceived.
The woman was so fearful of losing her daughter that she went on the run with her baby. She had previously lost custody of a son she had with the man, who had a history of violent offending.
The latest shocking revelation comes as Oranga Tamariki is increasingly underfire for its processes. Three Government ministers are heading to the Hawke's Bay today amid deep concern in a separate case involving attempts by staff of the agency to remove a newborn baby from its mother.
The mother of the 6-month-old girl wants Oranga Tamariki, the Ministry for Children, to apologise for their blunders and what she described as "heavy handed" treatment.
"They have made my life hell," she told the Herald on Sunday.
"When I had my daughter they insinuated her father was also my ex-partner. But that was impossible. He was in prison at the time."
Irate her contact details and other confidential information from an Oranga Tamariki file were sent to her ex-partner, the woman claimed a support worker asked: "Is she a Tinder baby?".
"They are constantly judging me even though I have turned my life around."
DNA results seen by the Herald on Sunday indicated the two siblings were 960,000 times more likely to be half siblings than full.
The woman said: "I knew that would be the case. I thought they are wasting taxpayers' money. What they did was disgusting - they should apologise."
The mother volunteered to take the test to prove her children had different fathers but couldn't reach an agreement with Oranga Tamariki where tests for her son should be done.
The delay prompted Oranga Tamariki to send the mother an email stating: "Whilst touching upon XXX's (the child's name) birth your client should be advised that her prevarication and subsequent refusal to consent to paternity testing leaves Oranga Tamariki with no alternative but to form its own conclusions as to the identity of XXX's father and the credibility, or otherwise, of your client's alleged inability to name the father. Your client is invited to urgently reconsider before Oranga Tamariki takes action on the basis of conclusions it might otherwise draw."
Fearing her baby was going to be removed, the mother bundled her up and went on the run.
"I knew if I refused to do the DNA test they would form their own conclusions and use those powers to basically uplift my daughter. I was out the door after I got the email. I didn't want to go through the same emotional turmoil when they took my son."
Her boy, now 4, who was fathered by the recidivist violent offender, has been in state care for most of his life.
He is the subject of a Family Court case with the woman seeking to regain custody of the child.
The boy's mother - who has previous criminal convictions and is on a benefit - currently has to pay $92 an hour during four supervised visits with her son a year.
In a statement, Oranga Tamariki regional manager Waikato Sue Critchley said because the court action was still ongoing it did "limit what we can say about the situation as a whole".
"Since the mother had her new baby, we have worked with her in the best interests of the child," she said.
"This has included a DNA test to properly assess if there were any care and protection concerns. The baby is in the care of the mum, and they have good support around them."
The mother said she had learnt from her mistakes and felt "wronged" by Oranga Tamariki.
One of the woman's support workers told the Herald on Sunday she believed the mother had been "persecuted" and that she was a "good mum and has solid support around her".
And the support person believes the mum should be reunited with her son.
The mother said she adores "her precious bundle of joy" but is mindful Oranga Tamariki can knock at her door any time.
"It's frustrating forever having to prove to Oranga Tamariki I am worthy to be a mother to my own children. They have too much power and that constant fear knowing they can knock on your door and take your child is horrendous."
The agency has been under fire this month after criticism of some of its practices of uplifting babies, which has included a high number of Māori children.
The public outcry intensified after the department's repeated attempts to uplift a baby in the Hawke's Bay.
Former MP Dame Tariana Turia also called on the department's chief executive, Grainne Moss, to resign after Newsroom released a video of Oranga Tamariki staff trying to get a young Māori mother to hand over her 1-week-old baby to state care.
Children's Minister Tracey Martin confirmed yesterday that she would travel to Hawke's Bay today along with fellow ministers Kelvin Davis and Nanaia Mahuta to meet with representatives of local iwi Ngāti Kahungunu and the Māori Council.
It has also emerged that three Māori babies a week were being uplifted from their mothers. Of the 283 babies taken into care last year, more than 70 per cent were Māori or Pasifika.