Supporters have donated close to $200,000 for a six-month-old boy with Down syndrome whose Australian parents reportedly left him with his surrogate mother in Thailand.

The boy named Gammy was reportedly abandoned after the parents took his healthy twin sister to Australia.

Pattaramon Chanbua, already a mother of two, said she was paid about $16,000 to be a surrogate for an unnamed Australian couple. The 21-year-old was planning on using the money to fund her children’s education.

"Because of our family’s poverty and debts, the money that was offered was a lot for me," Chanbua said in an interview with Australian broadcaster ABC News.

Several months into the pregnancy, tests showed one of the babies had Down syndrome. Chanbua said the couple asked her to have an abortion, but she refused, believing it to be a sin.

When the young surrogate gave birth in December, the Australian couple took Gammy’s sister home with them, leaving the boy behind.

“The poor boy, this is the adults’ fault,” Chanbua said in the interview. “And who is he to have to endure something like this even though it’s not his fault?”

Gammy, who also has a life-threatening heart defect, requires expensive medical treatment – something Chanbua should now be able to afford after a flood of support over the Internet.

A donation page called “Hope for Gammy” on the crowd-funding website has seen more than 4,000 well-wishers from around the world pledge about $180,000 in the past 11 days.

The donations have been accompanied by a mix of support for Gammy – who is now reportedly fighting for his life in hospital – and vitriol for the parents who rejected him.

“The Australian couple are selfish and self-centered. I'm ashamed for their actions,” reads one comment. “All the donations for Gammy are incredible. And I wish Gammy and his mother all the best.”