New reports allege that the biological father of abandoned baby Gammy has a previous criminal conviction for indecently dealing with a child.

Nine News reports that the Western Australian man, aged in his 50s, was found guilty of offences against a 13-year-old girl, resulting in jail time in 1998.

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The man’s wife, Gammy’s biological mother, said that she was aware of his past, but claimed that he was a good man regardless.

The new information comes as the surrogate mother of baby Gammy insists that his biological parents saw him in hospital, despite their claims that they didn’t know he existed.

Surrogate mother 21-year-old Pattharamon Janbua has threatened to sue the biological parents of Gammy after they alleged that they were never told about him.

She claims the couple, who have not been identified, rejected Gammy and returned to Australia with his healthy sister.

According to a Fairfax report, Ms Janbua, who has been left to care for the Down Syndrome baby, says that the father, aged in his 50s, came to a Bangkok hospital to take care of the baby girl, but never cared for Gammy, who was in the next crib.

The father, who has remained anonymous, said that a Thai surrogacy doctor only told him about and his wife about the girl, and alleged that he was told the surrogacy agency no longer existed.

Western Australia Premier Colin Barnett said there is little his Government can do about the “sad and distressing” case.

– with ABC