The Department of Internal Affairs is looking into the case of a preschooler facing deportation from Australia because his mother has been unable to pass on her New Zealand citizenship to him.
An advocate for the family, David Faulkner, said the child's mother was born in Samoa but was taken to New Zealand as a child by her parents who were New Zealand citizens, and granted citizenship by descent.
She moved to Australia as an adult and was granted a visa like any other New Zealander.
"She just considered herself a New Zealander, she never realised that her New Zealand citizenship by descent had any drawbacks.
"Well, it didn't have any drawbacks for her, but it's had some significant ones for her child born in Australia."
Mr Faulkner said it was only when she applied for a New Zealand passport for her child that she learned he was not entitled to it.
Without New Zealand citizenship, he is not entitled to a visa to remain in Australia and faces deportation to Samoa.
Mr Faulkner said the family had exhausted all their appeals to the Australian authorities.
However, Minister of Internal Affairs Peter Dunne had the power to grant citizenship to the child of a New Zealand citizen by descent.
Whe considering an application, the minister can take into account whether the child has an "ongoing demonstrable link to New Zealand" or whether there are any exceptional circumstances or public interest involved.
A spokesman for Mr Dunne said he was unable to comment on the case as it was currently being considered by the Department of Internal Affairs.
Mr Faulkner said he knew of one other mother whose baby been denied a visa to stay in Australia, but there could be as many as 1500 children in the same predicament who did not know it.
He said Pacific Islanders from New Zealand rarely received permanent visas, which was the only way to citizenship in Australia.
Families 'ripped apart'
Legal experts have said the New Zealand and Australian governments have a responsibility to help children in this situation.
Marianne Dickie is the director of the migration law programme at the Australian National University in Canberra.
She said the regulatory conundrum that has caught these children actually clashes with Australia's Migration Act, which says children should have the same immigration status as their parents.
"It just looks like it was a mistake - I see the department may have in the past been able to turn a blind eye.
"But, as we all know, the Department of Border Protection is a bit stricter so maybe the departmental officers don't have as much leeway."
She said, whatever the reason, the onus was now on the governments of New Zealand and Australia to fix it.
She said the Australian government could easily amend regulation to bring it in line with the Migration Act, or New Zealand could grant these children New Zealand citizenship.
New Zealand-based immigration consultant Cameron Gray, who spent 10 years working for the Australian Consulate-General in New Zealand, said he had seen families "ripped apart by temporary visas" on both sides of the Tasman.
He said the Special Category Visa, which gives New Zealanders the right to live and work in Australia, was not the same as having residency.
"Have a look at the criteria to meet residency. If you don't think you've got a shot at it, then if you go over there, you know that it's temporary, you know that your time there is short-lived and know the limitations of the triple 4 [Special Category Visa]. It is not residency."
A spokesperson for New Zealand's Department of Internal Affairs said officials were providing advice and guidance to individuals, and were also actively contacting people in Australia who may have citizenship by descent.
The department is working with Births, Deaths and Marriages in New South Wales, which sends a letter to New Zealanders registering a child's birth detailing citizenship by descent and what steps to take.
She said parents should contact Australia's immigration department as soon as possible to ensure their child holds an appropriate visa.