For Dylan Fraser, it is not so much a Ditch as a chasm.

He has a mother, two sisters, two children, and his friends on one side of the Tasman in Australia.

He is on the other side, in the North Island city of Hamilton where he lives by himself in a bedsit, working nights, after being deported from the country he has called home for most of his 23 years.

His parents moved from New Zealand to Australia seeking a better life for their children in 1998.

Mr Fraser was aged just 6, and now he speaks softly with the Australian drawl he picked up from 17 years living in Australia.

"What I know now, I learned in Australia. Good and bad," he says.

He has had a hard, scrappy life. He went to primary school in Sydney, and was diagnosed with ADHD at the age of seven and OCD at the age of 10. By 14 he was getting cautions from the police.

His mother, Deborah Lovett, battled to get him the help she felt he needed but he ended up in juvenile detention for three months for attempted robbery.

He had one relationship — and one daughter — and then formed another more lasting partnership with Ramona, and had another daughter.

Then in 2011, he took a baseball bat to another driver after a row on a Sydney street.

"I was just furious and angry," Mr Fraser says.

He went to prison, aged 19, for two years.

Prison brought him up short — and he was, he says, a model inmate who did not get a single charge during his two years inside.

"I made a promise to my family that I wouldn't fight," he says.

Mr Fraser did all the courses he was offered and stayed away from the gangs. Ms Lovett says prison helped straighten him out.

"That was the start of him actually getting better," she says.

He got out on parole, living with his partner Ramona and their little girl Bella, working two jobs.

New Zealand now second largest nationality detained

But as a New Zealand citizen living in Australia on a Special Category Visa, Mr Fraser was asked by Australian immigrations officials to justify why he should not have his visa cancelled.

He sent off a response and waited to hear back — then, five-and-half-months into his parole, he was picked up by the Immigration Department.

"There was no warning, no information. Five immigration officers, three police rocked up to my door when I was on my way to work," he says.

Dylan Fraser and his daughter Bella inside Villawood Detention Centre. ( Supplied )

He went from his home to the Villawood Detention Centre, where he stayed for 13 months, as he tried to fight his deportation in the courts.

But to no avail - and on June 2 this year, he was deported to New Zealand.

He can never return to Australia.

It was, Ms Lovett says, an ugly decision.

"You can't go back to a country where you don't know anyone," she says.

Mr Fraser has been presented with a bill of $58,154 for the legal costs of his failed appeals against the deportation, and been told he owes the Australia Government the cost of the flight to New Zealand for himself and the two officers who accompanied him.

He is one of the 80 New Zealanders deported so far this year from Australia, and more than 190 are currently in detention centres awaiting deportation.

New Zealanders are now the second largest category by nationality being detained.

The number has risen sharply since the Australian government tightened the laws in December 2014, meaning a 12-month prison sentence, rather than a two-year term, now triggers visa cancellation.

Key: 'There is an Anzac bond and an Anzac spirit'

It has been a shocking realisation for New Zealanders that Australia is rounding up and locking up New Zealand citizens, who have lived most of their lives in Australia, in detention centres as remote as Christmas Island, then deporting them across the Tasman.

It has not impressed New Zealand's prime minister John Key, who plans to raise the issue when his Australian counterpart, Malcolm Turnbull, makes his first overseas visit to New Zealand, later this week.

"There is an Anzac bond and an Anzac spirit. There's a special relationship that surely means that we might get some treatment that's different from other countries," Mr Key has told Radio New Zealand.

"I think when it comes to New Zealand, where the threshold is currently set is in the wrong place."

He wants Mr Turnbull to reconsider the deportations for people who have committed more minor crimes and those who have lived in Australia for most of their lives.

"If that doesn't happen, long term that's going to put any future prime ministers of Australia in quite a poor position in terms of their relationship any time they come over the Tasman to New Zealand," Mr Key says.

Dylan Fraser looks at photos of his family, who remain in Australia. ( Supplied: Philippa Stevenson )

It is a far cry from just a few years ago when Julia Gillard lauded the two countries' relationship.

When she addressed the New Zealand Parliament in 2011, the then-prime minister said: "New Zealand alone is family."

Part of that special relationship is the Trans-Tasman Travel Arrangement that allows Australians and New Zealanders to live and work in each others' countries.

It was, in fact, only in 1981 that New Zealanders even needed passports to cross the Tasman.

New Zealand, for its part, has deported just two Australians this year.

The country takes into consideration if Australians have lived in New Zealand a long time and allows people to apply to return to New Zealand after, at most, a ban of five years.

Policy does not reflect well on Australia, expert says

Professor Chris Gallavin, deputy pro vice-chancellor at New Zealand's Massey University and a barrister and solicitor, says the Australian law's failure to take into account individual circumstances means it is arbitrary and unjust – and the lowest form of buck passing.

"I'd like to think there is a semblance of cultural understanding between Australia and New Zealand and we'd have a more nuanced approach," he says.

Dylan Fraser with his family, back in Australia. ( Supplied )

And Professor Gallavin says the number of New Zealand citizens of Maori descent who are being deported does not reflect well on Australia.

He says that because Maori are over-represented in the criminal justice system - on both sides of the Tasman – they will be harder hit.

"It's not good enough for the [Australian] administration to ignore that issue, because that opens them up to criticism that it's a racist policy," Professor Gallavin says.

And he argues, the policy could come back to bite Australia.

"You don't do to other countries, what you don't want done to you," Professor Gallavin says.

Meanwhile, in Hamilton, New Zealand Mr Fraser has found work on the night shift at a plastics factory. He has got himself a small flat and a car.

He hopes his daughters will someday be able to come over to see him. For now, he works and stays out of trouble.

"I stay strong for my Mum," he declares.