Some oil has been detected on Rayong beaches, prompting officials to file complaints with police.
Masses of oil were found at PMY Beach in Muang district yesterday.
“They cause nausea,” said beach-watch volunteer Lamon Boonyong, 62.
Another volunteer, Rangsak Dokjan, said similar oil masses were found on Laem Charoen Beach a few days ago.
Bumrungsak Chatananwet, who heads the Marine and Coastal Resources Research and Development Centre for the eastern Gulf of Thailand, said it remained unclear where the oil came from. Last year, oil from a pipeline leak in the gulf hit some beaches in Rayong province.