BANGKOK — Hundreds of dead fish washed ashore on a luxury tourist resort on Thailand's south coast, officials said Saturday, blanketing a long stretch of pristine white sands in a rotting stench.

Some 300 meters (950 feet) of beach on Naka Yai island was littered with dead ponyfish, Phuket provincial fisheries chief Siripong Panasonthi told AFP, adding authorities were working to determine the cause of the deaths but had ruled out pollution in the water.

"We have checked the water quality... It cannot cause the fish to die en masse," Siripong said.

He said he believed the catch of ponyfish — which, when caught alive are sold to make animal feed but are worthless when dead — had been dumped by local fishing trawlers. — AFP