Thai police have launched probes into Islamic State involvement in southern Thailand following investigations and Australian reports linking "some Thais" to IS.
Thai police have repeatedly denied Islamic State activities in the region, where a Muslim insurgency since 2004 has claimed more than 6000 lives.
But Thai deputy national police chief Srivara Ransibrahmanakul told Thai media information provided by Australian authorities was part of a probe linking some Thais to Islamic State.
The Australian investigation also linked 100,000 Facebook users from Thailand visiting IS-related online communities in the past year, and revealed Thais were providing financial support to Islamic State.
Intelligence sources say the Australians avoid detection by Australian customs and immigration by initially travelling to Thailand on a six-month education or sports visa.
But upon arrival they make contact with IS links, are given a counterfeit passport and travel to Syria and Iraq from neighbouring countries.
After receiving training or fighting in the Middle East, they return to Thailand exchange passports and travel back to Australia without revealing they had travelled to the Middle East.
Thai Prime Minister Prayut Chan-o-cha said authorities were identifying the suspects and were prepared to take preventive measures and make arrests.
"The whole world is affected by the IS threat. Every country is facing this problem," Prayut said.
A recent report by the Sydney-based Lowy Institute warned the numbers of jihadists seeking to return to Australia is set to rise as Islamic State suffers military defeats and surrenders territory.
As many as 60 Australians have been killed in fighting with the jihadist groups in Iraq and Syria.
