Hua Hin beach was closed yesterday after an oil slick and foul smell forced tourists to leave.
The ten kilometer oil slick and large quantities of greasy garbage, including leaves, wood and coconut shells, blackened sections of the shoreline.
The oil slick forced Hua Hin mayor Nopporn Wutthikul to seek help from the navy to find out if it was caused by oil spills from commercial freighters or large fishing boats, reported ThaiPBS.
Tourists have been advised to stay away from the beach for 1-2 days.
Hua Hin deputy mayor Pailin Kongphan said it was the first time oil had washed up on Hua Hin beach.