The local people and tourism operators said the Ba Kantiang Beach on Koh Lanta has turned black from polluted water coming from a five-kilometre canal that runs through communities on the island.
The polluted water also emits a strong stench, troubling tourists.
The blackening of the beach happens during dry seasons, with rainy season clearing the beach and canal.
Wannah Hankla, 49, who runs a hotel on the beach, said polluted water is trapped on the beach during dry seasons, causing a stench.
He said he would like government agency to inspect the beach and find a measure to help end the pollution.
The one-kilometre-long beach is surrounding by cliffs and mountains. It was once so beautiful that it was a favourite location of foreign tourists.
Source : The Nation Multimedia