A six-month-old baby called Gammy has been left in the arms of his surrogate mother in Thailand, after his natural parents, an Australian couple, reportedly abandoned him.

The pair are said to have only adopted his healthier twin sister, having initially asked the surrogate mother to have an abortion after learning of the boy’s symptoms.

Gammy’s surrogate mother, Pattharamon Janburi, has vowed to care for the boy, but he is in urgent need of expensive treatment. An online appeal has already raised over 100,000 euros for his cause.

Pattharamon, already a mother of two, has spoken to Australian media about the boy’s plight, saying:

“This is the adults’ fault. Why should he have to endure something like this even though it’s not his fault? Why does he have to be abandoned when the other baby has been taken care of?”

The incident has already sparked uproar in Australia, where the identities of the parents involved remains unknown.

Australian Prime Minister Tony Abbot has been asked to comment on the situation:

“I guess it illustrates some of the pitfalls involved in this particular business,” he said.

“It’s a very, very, sad story and I hate to think that, you know, a child could be abandoned like that.”

Ms Pattharamon was reportedly paid over 11,000 euros to be a surrogate. A Thai health official has since commented that it’s illegal to pay for such a procedure in Thailand and that surrogates must be related to the natural parents.