Officials have raided three locations in Pattaya and seized computers and documents linked to a suspected nominee scheme concealing foreign ownership of land and businesses.
Officials conducted searches to gather evidence concerning suspected violations of the Foreign Business Act 1999.
The operation on Friday followed earlier investigations on Koh Phangan and Koh Samui in Surat Thani and in Phuket.
Evidence gathered indicated that Cosy Beach View Co Ltd in Chon Buri may have circumvented the law, leading investigators to seek warrants to search three locations.
At KT International Law and Business in Pattaya, officers found evidence indicating Thai employees of the law firm may have been listed as shareholders in Cosy Beach View on behalf of foreign beneficial owners. Documents were seized for further examination.
A second search at Shilat Avenue Pattaya Hotel found the hotel had hired the law firm to handle its registration and had listed law firm employees among its founders.
The third search targeted the Cosy Beach View condominium in Bang Lamung district, where an Israeli national was a company director. Its shareholding structure indicated Thai nationals had been used as nominees since 2010, police said.