The Western Australian couple embroiled in the controversy over baby Gammy say the child’s surrogate mother has been deceitful.

The plight of six-month-old Gammy, who was born with Down’s Syndrome and a hole in his heart, has prompted calls for reform of surrogacy services in Australia.

Impoverished mother Pattharamon Janbua told the ABC she gave birth to twins after agreeing to be a surrogate for the WA couple with a promised payment of about $16,000.

She claims the Australian couple rejected Gammy and returned to home with his healthy sister.

But in a statement via a family friend, the couple said Ms Pattharamon’s allegations are fabricated.

“This has been absolutely devastating for them, they are on the edge,” she said in a statement to the Bunbury Mail.

“Legally they have been told not to say anything but they wouldn’t be able to anyway.”

The Australian couple maintains they were not informed Gammy had Down syndrome, but were told of his heart condition and that he would not survive long after birth.

According to the family friend, the baby’s natural mother claimed she wanted to keep him to give him a traditional Thai funeral.

“Gammy was very sick when he was born and the biological parents were told he would not survive and he had a day, at best, to live and to say goodbye,” she said.