The Court of Appeal is set to reconsider the way New Zealand courts deal with the Hague Convention.
The Hague Convention determines the country in which a child custody case should be heard.
But with the majority of cases now involving mothers who are fleeing domestic violence, the Court of Appeal will reconsider a ruling from 1996 on when a child could be thrust into an intolerable situation.
The case the court will consider involves Jane, whose real name is suppressed.
She was psychologically and physically abused for several years before finding the courage to leave her former partner.
That was only after he was arrested and charged with assault after an incident in the house they shared with their young son.
She tried to get support which would have allowed her to stay in Australia, but was denied legal aid or a benefit from the Australian government.
As a result, she returned to New Zealand with her son, and months later she was being asked to return to Australia, and into the arms of her abuser.
The Family Court ruled that would have put her son at grave risk and into an intolerable situation but, on appeal, the High Court reversed the decision.
Jane's lawyer, Daniel Vincent, has now been granted leave to appeal the High Court decision.
The case could be the catalyst for a major change in approach when it comes to Hague Convention cases.
"The Court of Appeal has indicated that it will consider an authority from 1996 called 'A versus the Central Authority', where the issue of intolerable situation was considered by the Court of Appeal," Mr Vincent said.
"A more traditional and conservative approach to the application of the Hague Convention was taken in that case."
As things stand, the law has a very narrow definition of an intolerable situation. It only considers whether it is likely that the child would be at grave risk.
It does not consider the consequences for a parent who is being forced back, or the effects that could have on the child.
For that reason, Mr Vincent said the law needed to be reviewed.
"I think the time is right for the Court of Appeal to look at this again," he said.
"There is a real need for the Court of Appeal to reassess the intolerable situation defence in light of changes overseas, and also in light of what the reality of the situation in Australia is for New Zealand citizens.
"Our hope is that this case can effect real change in the way that the Hague Convention is applied for other women who are in the same situation as our client."
Because of the importance of the ruling, the established Court of Appeal barrister Ben Keith has joined Mr Vincent's legal team to help fight the case.
Ang Jury, the chief executive of Women's Refuge, has aided Jane since her return to New Zealand.
She said a win in the Court of Appeal would not only be huge for Jane, but also for up to 40 parents who go through the Hague Convention process in New Zealand each year.
"It is something that needs to be urgently looked at," Dr Jury said.
"It isn't fit for purpose. It was maybe fit for purpose back in the day, but it's just so not anymore."
Another mother who was forced back to Australia said she was homeless for two months after being returned, and spent six months in hiding from her abusive former partner.
She said this case would be a huge win for victims of domestic violence.
RNZ reported last week that she was allowed to return to New Zealand, and even take the father's name off the birth certificate after he declined visitation.
"I mean, obviously not every case is the same," she said. "There are fathers out there that want to be fathers.
"But it's coming out, more often than not, that there's mothers in the same situation. And I wouldn't want anyone to be in the situation that we were put into."
The Court of Appeal is yet to set a date for the hearing, and cases typically take up to a year to be heard.
During that time, the mother, Jane, will be able to remain in New Zealand to raise her son.