Volunteers are busy this week cleaning up an oil spill that washed up on beaches in southern Thailand.

The black goo emerged on the idyllic coastline stretching from Phuket to Phang Nga in the south of the country on August 5. It is believed to have originated from a tanker that was anchored off the coast of Phuket.

Officials said the oil pollution has forced the closure of several beaches, including Patong Beach, one of the most popular tourist destinations in the region.

It was expected to take around 3-7 days to wait for laboratory results to verify the type of oil involved in the incident. Around three tonnes of the dried substance have so far been found on beaches.

State official Pornsri Suthanaruk, the Deputy Director-General of the Department of Marine and Coastal Resources, said the oil slick had blighted the shores of Sirinat National Park and Koh Racha Yai.

He said that the region's stunning coral reefs - popular with divers from around the world - were at risk.