The biological parents of baby Gammy said they wanted him well as his twin sister but they feared losing both children when the surrogate mother threatened to involve the police.
David and Wendy Farnell were criticised for leaving the seven-month-old in Thailand after finding out he had Down's syndrome, while returning home to Australia with his healthy sister Pipah.
But the pair told 60 Minutes on Australia's Nine Network that they had little choice but to leave Thailand after the children's surrogate mother, Pattaramon Janbua, warned that she would involve the police and try to keep both children if they attempted to take the boy as well.
David Farnell, 56, said: "We wanted to bring him with us," adding that he and his wife still wanted the infant, who is being treated in a Thai hospital for a hole in his heart and a lung infection.
More top news
ITV News went undercover with a secret anti-poaching taskforce in Tanzania as they tackle the still-thriving ivory industry.
Largely dry, wind and rain arriving to the northwest tonight
Heartbreaking notes show Ayesha Ali's despair as she tried to please her mother, who - with her lover - tortured her for being "evil".