Australian Human Rights Commission president Gillian Triggs is investigating the case of three young Sydney siblings who fear their parents are about to be deported to Tonga.
Siofilisi and Ilisapesi Misinale arrived in Australia almost 25 years ago and subsequently overstayed their tourist and student visas.
Since then, the Immigration Department has refused the couple's requests to obtain permanent visas and the family claims the department has threatened to send them back to Tonga.
The couple have three children who are all Australian citizens, including a 17-year-old daughter who is still in high school.
The family have been living in Hillsdale, in Sydney's south, since 1992.
Youngest daughter Melenaite Misinale said her family had tried to convince the Immigration Minister Peter Dutton to intervene in their case but had been unsuccessful, and former Labor ministers had also refused.
She said her father worked six days a week as a storeman and a forklift driver to support his children through school and university.
"My siblings and I are going to have to seek other ways to support ourselves if our parents are given the final conclusion that they aren't able to remain in Australia," Misinale said.
"We're a family. We'd like our parents to be with us to keep our family united."
Her mother, Ilisapesi, said she and her husband have been told they have exhausted all options to obtain permanent residency in Australia.
"It's very unfair because I have three Australian children here. I just want to see if they have mercy to give me a chance to stay together with my family," she said.
The Misinale parents are now on bridging visas, awaiting another meeting with the Immigration Department.
A spokesman for Dutton said the family's case was still under review and the department had to consider several factors when deciding whether people could stay in Australia.
Twenty-year-old eldest daughter Daffofil said she and her brother were advised they would have to support their younger sister.
"It doesn't look right. Nowadays things are expensive," she said.
Immigration lawyer for the family Christopher Levingston said he was disappointed with the department's dealings with the Misinales.
"The attitude of the Immigration Department really has been 'this is your problem, we don't care, go back to Tonga'," Levingston said.
He conceded the Government could not approve every application, but said he thought the Minister would take a closer look at the case.