Mystery oil spill at Koh Larn spreads to Pattaya’s Jomtien Beach

On August 9, a black, oily substance washed onto beaches on Koh Larn, the island off Pattaya's coast in the Gulf of Thailand. It hit Tien Beach and Samae San Beach around midday. The substance coated more than a kilometre of the island's western shoreline. Swimmers came out of the water covered in the material.

By August 10 the slick had reached Jomtien Beach on the Pattaya mainland. Pattaya City closed Jomtien to bathers while environmental investigators collected samples. No health complaints or injuries were reported.

Authorities have not confirmed the source. Pattaya Deputy Mayor Manoch Nongyai said two possibilities are being examined: a vessel dumping oily waste illegally offshore, or material that drifted from Laem Chabang port, around 15 kilometres to the north. The Marine Department is leading the investigation.