An Australian couple, who were accused of abandoning a baby boy that they had with a Thai surrogate woman because he had Down's syndrome, has denied the accusation and said they would fight to get the child back.

The case sparked international outrage after the couple flew back to Australia with the boy's healthy twin sister Pipah, leaving Gammy with the surrogate mother Pattaramon Chanbua.

In an interview broadcast on Sunday, David Farnell said that he and his wife wanted to bring Gammy with them, but feared Chanbua, who reportedly demanded to keep the children, would call the police and take both of the babies from them.

"We never said you (Pattaramon) can have this baby, no matter what," said David Farnell, in an interview with the Channel Nine news channel.

The couple claimed Pattaramon also wanted to keep the girl and said they left Thailand without Gammy because "we were getting scared that we would lose her too and we had to try and get her out".

The Farnells, from Bunbury south of Perth, Western Australia, previously claimed they were told Gammy had a congenital heart condition but not Down's syndrome, and left him because doctors said he would not survive.

Gammy, now seven months old, has since been cleared of a heart condition by Bangkok specialists, an Australian charity which has raised more than $240,000 for the infant said on Friday.

The charity, Hands Across The Water, said the boy had been released from hospital - where he was being treated for a lung infection - and was living in Bangkok with his family. 

Abortion claim

Chanbua claims the agency that acted as the go-between told her the Farnells wanted her to have an abortion - which is illegal in Thailand - once medical tests revealed the boy had Down's syndrome, but she refused.

"We never abandoned him, we never said to the surrogate mother 'have an abortion'," said David Farnell, although he admitted it crossed their minds.

"Because he has a handicap and this is a sad thing. And it would be difficult, not impossible, but difficult."

Farnell also admitted the couple had not tried to contact Gammy since they left Thailand to check on how he was.

"We have been trying (in Australia) to make sure first that Pipah is safe and no one can take her away from us," he said, explaining that as she was born in Thailand she was not yet legally Australian.

"When we know 100 percent that she is safe with us, we can go and try to get our boy back."

Their comments came as Canberra urged Thailand to allow for a transition period before implementing any ban on commercial surrogacy to protect earlier arrangements made by Australians.

The Thai government is proposing tighter controls on commercial surrogacy in the wake of the Gammy scandal.

Source: Agencies