One of the same-sex couples was travelling with the surrogate mother.

The airport intervention comes after it was revealed up to 150 Australian couples caught up in Thailand’s crackdown on surrogacy will have to obtain permission of the country’s Family Juvenile Court to take home their babies born to Thai surrogate mothers.

This requirement, and stricter document requirements, will cause agonising months of waiting for the parents before they can leave Thailand with their babies, surrogacy experts say.

Thai immigration authorities have advised the Australian embassy in Bangkok the parents will require an order of the court confirming the birth mother has given up her rights to custody of the child.

The embassy has been told that if airport immigration officials suspect a child has been born by surrogacy in Thailand, parents will be required to provide the child’s birth certificate, copy of the mother’s identification card, copy of the intended parent’s passports and the surrogacy contract.

“We strongly urge Australians entering Thailand for the purposes of commercial surrogacy to seek independent legal advice in both Thailand and Australia before doing so,” a spokesman for Australia’s Department of Foreign Affairs said.

“While regulation of surrogacy in Thailand is a matter for Thailand, we continue to encourage Thai authorities to adopt appropriate transitional arrangements for any new measures they may introduce, so concerned Australians are not unduly affected,” he said.

Sam Everingham, founder of Surrogacy Australia, said the confirmation that a court order will be required, which was earlier revealed by Fairfax Media, will at least provide “some clarity” for parents deeply distressed by the crackdown and who were previously uncertain they would be allowed to take their babies home.

Thailand’s military rulers have fast-tracked draft laws for the country’s parliament which ban commercial surrogacy except involving family members.

Sappasit Kumprabban, a veteran child-rights activist who participated in drafting the laws, said they will have retrospective effect in terms of the status of a child born through surrogacy. However the punishment for commercial surrogacy will not be retroactive.

“Assuming the bill is implemented today, a surrogate child born before or after law enforcement will be automatically the legitimate child of the commissioning parents,” he told the Bangkok Post.

Mr Sappasit said there is no problem if the fertilised embryo is produced from the commissioning parents' egg and sperm.

“But if it is produced by donated sperm and the egg of a commissioning mother, or by donated egg and sperm of a commissioning father, the bill provides a route for the commissioning mother and father to claim parental rights over the child,” he said.

Mr Everingham appealed to Thai authorities to allow Australian couples to take their babies home for a temporary period before returning to Thailand to petition the court for parental rights.

Australian officials in Bangkok have been pressing Thai authorities to allow a moratorium for Australians who have existing arrangements with Thai surrogates amid a crackdown on commercial surrogacy after Fairfax Media revealed the plight of baby Gammy, which caused a furore in both Thailand and Australia.

Pavena Hongsakula, a leading Thai woman and child rights activist, urged parliament to pass the laws urgently because “our country is not ready to cope with commercial surrogacy”.

But she said the Australian couples with existing arrangements should have their backgrounds checked before they can take their babies.

“These couples are in a very difficult situation … they came to Thailand probably believing they were not breaking any laws,” said Ms Pavena, a former Social Development Minister.

“But the interests of the child is the most important thing. The biological parents should be subjected to extensive background checks and then only be given the babies on a case by case basis,” she said.

The Medical Council of Thailand has set-up a committee to investigate the baby Gammy case and two doctors who were allegedly involved in the births.

Medical authorities are also investigating doctors behind All IVF Centre, the most popular surrogacy clinic for Australians, which has been forced to close after being linked to a “baby factory” case where 24-year-old Japanese businessman Mitsutoki Shigeta fathered at least 15 children to 11 Thai surrogate mothers.

A new study commissioned by Surrogacy Australia suggests laws banning overseas surrogacy hold little sway with prospective parents considering the procedure. Published in the Medical Journal of Australia, it found only nine per cent of respondents to an online survey would rule out paying a woman living overseas to have their baby if it was illegal.

Many also said they felt it unfair to ask someone to carry their child without payment.

Monash University’s Karin Hammarberg said Australian governments should consider legalising paid surrogacy so it could be properly regulated.