Customs officials seized a modified fishing boat with 50,000 litres of smuggled diesel in the Gulf of Thailand about 11 nautical miles west of Koh Samui off Surat Thani province on Tuesday and arrested the boat's skipper and a crewman.
Nimit Saeng-ampai, chief of the Ban Don customs office in Surat Thani, said at a press conference on Thursday morning that the seizure was part of a drive to suppress oil smuggling.
Sommat Boonchudam, 62, the boat's skipper, and Jirapong Boonchudam, 58, were arrested on board the modified fishing boat with 50,000 litres of diesel worth about 1.2 million baht. The two said they received a monthly pay of 15,000 baht from a man identified only as Phan to deliver smuggled oil.
Mr Nimit said the fuel was smuggled from Malaysia and destined for Vietnam.