Her case has raised fears of financial clawbacks for other New Zealand surrogates, including an Auckland woman who is eight-months pregnant with a son to another gay Australian couple.
"She's told the couple they have to sort it out as there's no way she's paying," said the second surrogate, who declined to be named.
"The deal with them is 'You guys sort out the legal stuff and the financial stuff.' I hope this doesn't happen to me but the boys will sort it out. It gets complicated with the guy thing."
It is understood the one-year-old surrogate baby girl is being raised by the baby's biological father and his male partner in Queensland, who are her legal guardians. They gained child support benefits for the father to stay home and care for her, as new parents are entitled to. However, authorities asked the surrogate to contribute, which she refused to do.
Unlike in New Zealand, surrogacy is illegal in Queensland and many parts of Australia.
Australian funding agencies Centrelink and the Child Support Agency confirmed they were likely to seek maintenance payments from a birth mother in New Zealand if the Australian birth father claimed benefits as a sole parent caring for their baby.
Family law expert Professor Mark Henaghan, dean of law at Otago University, said surrogates could be forced to pay child support on either side of the Tasman if their babies were not adopted and the intended parents claimed benefits. Gay male couples were unable to adopt in New Zealand and in most of Australia, which meant the surrogate mother's name remained on birth certificates and prevented her signing away legal rights to the child, he said. Guardianship was insufficient to remove the birth mother's legal duties.
"You can't contract out of child support," Professor Henaghan said.
"It's a blanket rule. The circumstances are irrelevant. If you are a parent, unless someone adopts a child, you are the legal parent."
According to the co-owner of the nz-surrogacy.com website, Amanda MacLeod, adoption occurred in about half the surrogacies in New Zealand and guardianship arrangements covered the rest. "As if surrogacy isn't hard enough, the only choice you've got as a gay couple is to have surrogacy. There's only one sort of box you have to fit into," she said.
Under New Zealand's 1955 Adoption Act, only married and single people are allowed to adopt. A single person can adopt regardless of sexual orientation but a single man is banned from adopting a girl unless under specific circumstances.
Professor Henaghan, a member of an adoption reform group which has lobbied for same-sex adoption and other adoption law changes, knew of only one case of a single gay man adopting a child in New Zealand and none trying to adopt a surrogate child. The act appeared to allow gay men to adopt a surrogate child, he said.
In September 2007, the New Zealand Family Court allowed an uncle to adopt his two-year-old nephew, whom he had raised since birth. At the time, the judge said it was the first case of a gay single man adopting.