A Brisbane couple is fighting to stop their two-year-old son from being deported.

A Brisbane couple is fighting to keep their adopted two-year-old son who will be deported to Manus Island unless he is granted permanent residency in Australia.

Craig and Karen Wells are the legal guardians of the Papua New Guinean toddler, Mackalistair, but fear they could lose him, despite having cared for him for the past 15 months.

“I’m Australian, Karen’s Australian, Mac is our son and he’s Australian,” Craig told Mamamia.

“It’s against Australian law for us to abandon a child. What sort of cold person would do that?”

Mackalistair's adoptive parents fear he could be deported to PNG. Source: change.org

Mackalistair came to be in the Wells' care after his biological father tried to give him away.

"His father worked with my wife at a detention camp, Mackalistair Senior. He asked if she wanted a baby, she said 'yeah I’ll have a boy', jokingly.

"It was a week later when he was born ... Mackalistair Sr came to Karen at work and said 'your baby is here'."

The couple say they had no intention of adopting the child at first but changed their mind once it became clear he would otherwise be abandoned.

"We were encouraging the family to keep him. When he was three weeks old I took him to Port Moresby to be with his grandmother and his auntie and we supported him the whole thirteen months he was there.

"I flew his biological father [when he was] 6-months-old to Port Moresby to support him, hoping he would grow attached and take him back to Manus Island, but that didn’t happen."

Craig and Karen Wells. Source: Facebook

In March 2015, the Wells brought both Mackalistair and his father, through appropriate legal channels, to their home in Brisbane's Deception Bay, but after just five days his father chose to return to Manus Island without him.

"Right or wrong the parents didn’t want him back."

Informal adoptions are very common in PNG and many children are either given away, abandoned or sold into servitude — many end up on the streets.

"Karen and I, while he’s here, we want to make him the best person he can be and when he’s older, if he wants to, he can take that knowledge and ability back to Papua New Guinea and help other children over there," Craig said.

Mackalistair has been living in Brisbane for more than a year. Source: Facebook

The Department of Immigration and Border protection are "aware of this case" and confirmed Mackalistair may be suitable for an 837 visa designed to "cater to exceptional cases in which a child's parents are reasonably believed to be dead, missing or permanently incapacitated", however the decision must be made by an independent tribunal.

"All visa decisions are made on their merits in accordance with relevant legislation," a department spokesperson told Mamamia.

In the meantime, the staff from Mackalistair's childcare have launched an online petition urging them to let him stay and are fundraising to hire an immigration lawyer to act on the Wells' behalf.

"He’s such a happy and cheeky kid, it’s heartbreaking to think he could now get ripped apart from his adoptive parents," the change.org petition reads.

"Basically I love him, Karen loves him and the rest of our family loves him too," Craig said.