A sea turtle was rescued after being found ensnared in a fishing net and covered in oil from a spillage that has blighted beached in southern Thailand.

Fishermen noticed the large marine creature struggling on the surface of the water off the coast of Phuket on Friday morning at around 8:30 am.

They placed it in a tub while pushing it ashore, where wildlife workers untangled the ropes and began washing the oil from its body.

Staff from the Phuket Marine Biological Center are now caring for the turtle as volunteers continue cleaning globules of oil from large stretches of the idyllic coastline with the Andaman Sea.

The oil slick was first noticed on August 5 and is believed to have originated from a tanker that was anchored off the coast of the island.

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

They warned that the stunning coral reefs - popular with divers from around the world - were at risk. Marine animals and local fisherman have also been affected.

Prarop Plaengngan, the chief of Khao Lampi–Hat Thai Mueang National Park said that a fresh wave of oil stains was affecting Hat Thai Mueang in Phang Nga province.

Officials said a layer of greasy black oil, resembling asphalt, that was beginning to solidify, with some portions broken into small crusts.

After conducting inspections across 13 locations, they observed oil spill patches ranging from three centimetres to 40 centimetres in size, averaging around five patches per square meter.

They estimated that there were more 65,000 oil spill patches across the Hat Thai Mueang beach, some 10 miles long.

The government officer Prarop Plaengngan said those responsible for the spill had not been found.

Prarob urged all sectors to come together in a voluntary effort to clean the beach until the oil stains were fully removed.