The priority is to try to determine whether the clinic in Thailand that carried out the operation for an Australian couple was registered with a regulatory body.
Arkom Praditsuwan, a senior ministry official tasked with the probe, said operators that fail to register with the Royal Thai College of Obstetricians and Gynaecologists (RTCOG) but do surrogacy would be subject to up a year in prison and/or a fine of up to Bt20,000.
They could also have their licence revoked if found guilty by the Medical Council of Thailand in a further investigation into the morality and professional ethics of the case.
Arkom later said it was likely that a private clinic, which has now closed down, performed the surrogacy in question, with the twins - the boy with Down's syndrome and his sister - delivered at a large private hospital located in surburban Bangkok.
The director of the Bureau of Sanatorium and Healing Arts under the Department of Health Service Support has said there are seven clinics licensed to do surrogacy operations while another five are suspected to do them illegally.
A probe was also underway into the doctors who performed the surrogacy in question - whether they were granted a licence by the RTCOG. Arkom said they would be penalised by the Medical Council if found to have operated without a licence.
Secretary-general of the Medical Council of Thailand, Dr Sampandh Komrit, said there were 45 qualified surrogacy experts registered with the Royal Thai College. Those found to have done this surrogacy case would ultimately face having their medical licence revoked, or suspended and on probation, or disciplinary action for lesser offences.
Under regulations in Thailand, a surrogate can only accept an embryo from a mother who is a relative (and her husband). It is illegal for money to be given to the surrogate who bears the child.
The Australian media reported yesterday that the Australian man in this case denied abandoning the Down's syndrome boy while taking his healthy twin sister back to Bunbury, a small town south of Perth.
The unnamed father said a Thai doctor had only told them about the girl. He told the ABC there had been many problems with the surrogacy agency, which he was told no longer exists.
The mother Pattaramon Chanbua, 21, was lauded by Australian Immigration Minister Scott Morrison for agreeing to take care of the boy, whose condition was regarded as "life-threatening", hailing her as "a saint".
"It is terrible, just absolutely horrible and heartbreaking," Morrison said of the case. "But I have got to tell you who is an absolute hero in all of this and that is the Thai mother. She is a saint," Morrison was quoted by AFP as saying.