The national committee on repatriation of stolen artefacts will pursue another three historical artefacts displayed in museums in the US and UK, says Itthiphol Kunplome, the culture minister.
"Officials have checked with archaeological database and photos, and ascertained that these objects were artefacts smuggled out of Thailand," Mr Itthiphol told the media on Wednesday.
They are a Buddha statue believed to have been removed from Sap Champa Ancient City in Lop Buri province, and two "sema" (Buddhist's temple boundary markers) believed to have been stolen from Kao Daet Song Yang Ancient City in Kalasin province.
The Buddha statue is on display at the Asia Society in New York City, and the sema objects have been displayed at the British Museum in London.
In a related development, the US state attorney in New York State will today return 13 smuggled artefacts, mostly Buddhist statues, to the Royal Thai Consulate in New York City.
These artefacts are among 1,000 stolen artefacts and antiques which have been confiscated by the US's Antiquities Trafficking Unit (ATU). The ATU has checked and found they are of Thai origin.
They would be sent back to Thailand next month, along with two lintels.
The two lintels -- one originally from the Prasat Khao Lon historical sanctuary in Sa Kaeo and the other from Prasat Nong Hong in Buri Ram -- were believed to have been stolen in the early 1960s and later were found displayed at the Asian Art Museum in San Francisco.
The lintels are to return to Thailand by next month in a ceremony presided over by Prime Minister Gen Prayut Chan-o-cha.
Afterwards, the items will be displayed from May to July at Bangkok National Museum near the Grand Palace.