Nimit Saeng-ampai, chief of the Nong Khai customs checkpoint, where six Thai suspects were detained on Saturday after returning from Laos, said the Public Health Ministry would follow up on this case.

Multiple tubes taken from the suspects and their driver would have to be tested in the laboratory to see if they contain any genetic materials for use in the assisted reproduction process, he said.

Nimit said Nikom Simarat, who drove the six Thai suspects across the border to a Laotian fertility clinic, would face an additional criminal charge if traces of genetic materials were found in the containers, as such smuggling would violate Thai law.

According to Thai authorities, Thai fertility clinics are believed to have cooperated with counterparts in Laos and Cambodia to provide cross-border surrogacy services in which Thai women would be hired as surrogate mothers by foreigners, especially Chinese.

These women, who are married and already have their own children, would be impregnated and paid a fee of Bt100,000-400,000 each once the babies are born.

Since the Thai law against surrogacy-for-hire services is strictly enforced, the network and their clients have to smuggle surrogate mothers into neighbouring countries for the assisted reproduction techniques. Afterwards, the surrogate mothers return to Thailand and, after nine months, go abroad again to deliver the babies.