The plight of Kiwis being held in detention centres is now the subject of an official complaint to the Australian Human Rights Commission.
The Greens from Australia and New Zealand will lodge the complaint and the announcement comes on the day new Australian Prime Minister Malcolm Turnbull arrives for his first trip to New Zealand.
Pressure is ramping up on the Australian policy which sees non-Australians who have been sentenced to 12 months' or longer in prison deported.
New Zealand Greens' human rights spokeswoman Catherine Delahunty is concerned about human rights breaches for the around 200 Kiwis in detention centres around Australia, including 40 on Christmas Island.
Many of those Kiwis have very few connections to New Zealand, having spent much of their lives in Australia.
"There are appalling stories out of Christmas Island in particular. New Zealanders in detention are being bullied by guards, there is a lack of access to medical treatment, they are not able to access legal support and a number are subject to arbitrary detention," she says.
Australian Greens' immigration spokeswoman Senator Sarah Hanson-Young says the special trans-Tasman relationship is being put at risk by the policy.
"This is a real test for Malcolm Turnbull and he will have some serious questions asked of him when he lands in New Zealand today. Will he let the vestiges of the Abbott government’s overreach on immigration law hurt our regional partnerships or will he see sense and let the courts consider these matters on a case-by-case basis?"
Hobart barrister Greg Barns has taken the case pro-bono.
The New Zealand Parliamentary Human Rights Committee has also called for urgent action on the reported human rights breaches resulting from the policy.
Committee co-chairs Chester Borrows, Catherine Delahunty, Marama Fox and Sue Moroney say the breaches include the right to legal assistance, to contact family and protection from arbitrary detention.
They also say there has been a breach of natural justice because people who have completed their prison sentences are being detained as criminals and threatened with deportation.
Mr Turnbull arrives in Auckland tonight where he will have a private dinner with Prime Minister John Key, followed by a bilateral meeting tomorrow. Mr Turnbull will also meet with Labour leader Andrew Little tomorrow.
Mr Key says he will raise the issue with Mr Turnbull to try and find a diplomatic solution to the problem.
"I think he'll definitely listen and I can definitely give New Zealanders an assurance I'll do everything I can to get what I hope would be a better deal for New Zealanders," he said yesterday.
Labour's corrections spokesman Kelvin Davis has travelled to the Villawood Detention Centre to "fight for the rights" of Kiwi detainees.
He has met with families of those who have loved ones in the detention centres.
Mr Key labelled Mr Davis' trip a "political stunt".