The mayor of Phuket's Karon municipality has denied that a black stream running from Karon beach into the sea is polluted water, saying it is the colour of sediment while the water is actually crystal clear.

Jadet Wicharasorn was responding on Tuesday to aerial pictures of Karon beach that have gone viral on social media. They showed a black stream flowing through the beach into the sea.

Mr Jadet said the water came from Nong Han pond near the beach. It was black because a high tide had reached the pond and when it retreated, it drew black sediment from the pond through the sand and into the sea.

“I insist that the water is not polluted. Polluted water would have blackened all the seawater along the beach,” he said.

Mr Jadet said he ordered a water quality contractor to check the seawater in the area and “collected samples are crystal clear and odourless”.

To solve the problem, he said, the municipality would dig holes to trap sediment upstream.