A young Kiwi mum, on the run from the FBI after allegedly kidnapping her baby daughter, says she is throwing herself on the mercy of the New Zealand justice system.

Bianca Ellen Ormsby has used Facebook to try to explain why she fled the United States with 12-month-old Sydney Moana Thomas in the middle of a custody dispute with the baby's Michigan father.

She said the father, Adam Thomas, had endangered her and baby Sydney Moana through public statements about their disappearance.

In messages to the Herald on Sunday, she said she received hate mail and death threats since leaving America.

"I want me and Sydney to remain safe from this mess," she said.

She has hired a lawyer to fight the case. "I am setting it straight in court with the facts."

Court documents obtained by the Herald on Sunday show Ormsby, 21, is wanted for the international parental kidnapping of her daughter in March. A warrant was issued for her arrest by the magistrates court in Detroit on May 18.

Supporters of Ormsby had set up a Facebook page entitled "Bianca sets the record straight", which had nearly 600 members last night.

Postings on the page claimed Sydney suffered head injuries following a visit to Thomas' house and had to be rushed to hospital. On February 21, Ormsby posted a Facebook status update: "hmm i don't mind hospitals when im the one working there ... i hate them when im there for my daughter ..."

However, Thomas, who spoke to the Herald on Sunday from Michigan, said an investigation completely cleared him of any wrongdoing.

Sydney had fallen while trying to walk, he said. He believed somebody had made an anonymous report to the state's child protection services.

"Sydney had just started trying to walk, she was standing up, she was 10 months old and she was climbing up a door-frame and she fell, just like babies do. An investigator came out, he looked and saw that nothing had gone wrong and that was it. It was kind of bogus."

A distraught Thomas said he had approached the local court several times since July last year, concerned that Ormsby would take their baby out of the country. He just wanted his daughter back, he said.

"It's been almost three months, I miss my daughter a lot. I love her to death, I want to be able to see her."

Thomas' 47-year-old mother Kathy, who is terminally ill with breast cancer, desperately wants to see her grandaughter, he said. "She only has so much time left."

Thomas said he and Ormsby met while working for a vacuum cleaner company.

They dated for a few weeks before Ormsby became pregnant. Sydney was born on May 9, 2009. They lived together briefly before splitting when Sydney was 2-months-old.

Ormsby had called sporadically since disappearing from Michigan on March 9.

She told it was better for Sydney to remain in New Zealand, but Thomas said he still didn't understand why they had disappeared. This week, Ormsby posted a photo of Sydney Moana on her Facebook supporters' page.

"I would like to keep my daughter safe and out of public eye as she needs the most stable environment possible please i want to keep her safe thankyou," she wrote.

"Just to set the record straight. I am not wanted by the fbi i am following the legal system in new zealand. The police are aware of my situation and where i am and i have not been charged with kidnapping or abduction and i have been in contact with the father for the last few months. Thankyou."

However, the US District Court in the eastern district of Michigan has supplied the Herald on Sunday with a copy of an arrest warrant for Ormsby, and an affidavit sworn by FBI Special Agent James Brennan.

It states that Ormsby collected her daughter from Thomas' home on March 9. He has not seen her since.

Ormsby and her daughter boarded a Qantas flight to Auckland at Los Angeles International Airport on March 16, 2010, the FBI affidavit says, travelling on New Zealand passports.

The warrant alleges Ormsby "knowingly and wilfully" removed a child from the United States, with intent to obstruct the lawful exercise of parental rights.

Following confirmation Ormsby had left the country, Judge Brown granted sole temporary custody of Sydney to her father.

A spokesman for the New Zealand Police said the case is an FBI matter and as yet they are not involved.