An Australian couple has denied they abandoned one of the twin babies they had through a surrogate mother in Thailand.

The baby boy, named Gammy, and his sister were born two months prematurely. He has Down syndrome as well as a congenital heart condition.

The couple alleges their surrogacy agreement was made void by the fact that the babies were born at a different hospital to their chosen facility.

A friend of the couple has issued a statement on their behalf, saying they are traumatised by the events that have unfolded.

Sky News reporter in Australia Natalie Chenken told Newstalk Breakfast the couple claim they were told baby Gammy would not survive - and that their legal status put a question mark over whether they would be able to take his sister home: