“I will take care of my baby until I die ... no-one will take my baby away from me,” declared Pattharamon Janbua after the couple David Farnell and his wife Wendy broke their silence on Channel Nine’s 60 minutes on Sunday night.

“I want them to come to Thailand. I will take Gammy to see them. But they will never get my boy,” she said.

“You are dreaming. You are already guilty of abandoning Gammy and now you think you can get away with this.”

During the emotional interview Mr Farnell, a convicted child sex offender, vowed to claim six-month old Gammy and reunite him with his twin sister Pipah, but gave no detail how he intends to do that.

Under Thai law the Thai surrogate mother is the legal mother of a baby in all circumstances and the only way Mr and Mrs Farnell could take Gammy would be if Ms Pattharamon signed papers to agree.

Ms Pattharamon denies the claims made by the Farnells in the interview, insisting the couple abandoned Gammy after earlier asking her to have an abortion, which she refused because it is against her Buddhist beliefs.

Ms Pattharamon, 21, earlier told Fairfax Media that Ms Farnell was not the twin’s biological mother, saying she did not supply the egg that was implanted in her before she fell pregnant.

She said the egg came from a Thai woman through a surrogacy agency.

Mr and Mrs  Farnell told 60 Minutes they wanted to take Gammy and Pipah back to Australia but became concerned they would lose both babies when Ms Pattharamon threatened to report the couple to the police.

They say they never agreed to Ms Pattharamon's offer to look after Gammy.

‘‘We asked her can you please give us back our baby boy,’’ Mrs Farnell said. ‘‘She got very, very angry. She said if she cannot take (the) boy, she will keep both of them.’’

The couple said they decided to take Pipah home to ensure her safety before seeking advice on how to get custody of Gammy.

‘‘(The surrogate) said if we tried to take the baby boy she was going to get the police and she was going to keep both of them,’’ Mr Farnell said.

‘‘We were worried we were going to lose our daughter. We had to get our daughter home.’’

Ms Pattharamon angrily refuted the claim.

“I never said I would keep both babies and would go to the police … I only talked to the police when the (surrogacy) agent would not give me the money I was owed,” she said.

Claiming their visas were about to expire, Mr and Mrs Farnell left the country without attempting to extend their visas or seeking advice from the Australian embassy about taking Gammy home.

Since returning to their home in South Bunbury, Western Australia, the couple have only contacted the agency which brokered the surrogacy deal.

Mr Farnell said he sent the agency ‘‘a couple of thousand dollars’’ to go towards Gammy’s medical treatment.

Ms Pattharamon denied getting any money.

The couple also denied ordering Ms Pattharamon to abort Gammy due to his disability but admitted they were angry to discover he had Down syndrome so late into her pregnancy and asked the agency for a refund.

‘‘(I said) ‘Give us back our money. This is your fault’,’’ Mr Farnell said.

He admitted that had he known about the disability earlier, he would have insisted Ms Pattharamon abort the foetus as no ‘‘parent wants a son with a disability’’.

60 Minutes' interviewer Tara Brown described the Farnells as ‘‘the most hated couple in Australia’’ before quizzing Mr Farnell about his history of sexual offences against girls as young as five.

Asked whether Pipah would be safe in his care, Mr Farnell replied he no longer had sexual urges towards young girls after undergoing counselling in prison.

‘‘I don’t have this urge to do anything anymore,’’ he said. ‘‘She will be 100 per cent safe. I will do everything in the world to protect my little girl.’’

"I have been convicted of child sex offences and I hang my head in shame for that and I am deeply regretful and I am so sorry to those people,’’ he said.

The 56-year-old, who also has three adult children, said that he realised he had done the wrong thing after thinking how devastated he would be if someone sexually abused his children.

The couple underwent IVF treatment for eight years before engaging a surrogate after Mr Farnell watched a television program about overseas surrogates.

He admitted he did some research on the internet but ‘‘not a lot’’ before visiting clinics in Thailand and then signing a contract with an agency.

Mr Farnell initially denied knowing about Gammy after Fairfax Media broke the story of the baby boy's plight.

The story prompted Thai authorities to shut down Thailand's booming and largely unregulated surrogacy and IVF gender selection business.