The Office of Basic Education Commission (Obec) plans to send a circular notice to all school directors, urging them to carry out detailed checks on the criminal backgrounds of foreign teachers.
The move came after the arrest of convicted child molester Peter Dundas Walbran, 59, a former headteacher of the Australian International School in Jakarta, Indonesia, in Ubon Ratchathani on Wednesday.
Walbran, who holds both Australia and New Zealand passports, was taken into custody by Thai and Australian Federal Police, after his past convictions were uncovered.
He had served three years in jail in Indonesia for the rape and molestation of Indonesian boys as young as eight over a nine-year period there before travelling to Thailand to teach at a school in Ubon Ratchathani. He was ordered to register his Indonesian convictions with Australia's National Child Offender Register, but failed to do so. He then left Australia early this year on his New Zealand passport, police said.
Had he been on the sex offender register he would have been required to report his travel plans and Australian police would have alerted Thai authorities, police said.
Obec deputy secretary-general Suthep Chittayawong said the Education Ministry has come up with guidelines for school administrators who employ foreign teachers.
Foreign applicants are required to pass a criminal record check, and are required to have a degree and a non-immigrant "B" visa. They also need a teaching licence recognised by the Teachers' Council of Thailand.
However, he said Obec has found some foreign applicants have falsified their credentials because certain documents, such as fake degree certificates, are easily acquired in Thailand. Some unqualified foreign teachers may have fraudulently passed the screening processes, he added.
"I know some schools choose to hire foreign teachers first and run background checks on them later," Mr Suthep said.
"This is because language teachers are in high demand and the checking process usually takes time and is expensive for the schools. So we will write to school directors urging them to follow the rules strictly."
Asked about what he intended to do in Walbran's case, Mr Suthep said Obec will order the Secondary Educational Service Area Office 29 overseeing schools in Ubon Ratchathani to determine whether his employer conducted the required screening process.
Walbran was a convicted paedophile employed despite extensive media coverage of his prior crimes.
"If the school did not conduct the required screening process, it could face disciplinary action," he said.
Private Education Commission Office secretary-general Adinan Pakbara said he also warned private schools to tighten their employee screening system.
"Foreign embassies, the Immigration Bureau, the police and schools themselves should share information," he said.