The naked bodies of two British tourists who had apparently been attacked with a hoe have been found on a beach, police have said.

The pair were found with gruesome head wounds on Koh Tao, an island in Surat Thani province known for its diving sites and stunning beaches.

The victims' clothes and a hoe with blood stains were found nearby, Colonel Prachum Ruangthong from Thailand's police force said.

Police suspect the victims - a woman (23) from Norfolk and man (24) from the Channel Islands - were killed with the hoe, leaving deep wounds on their heads.

The pair had been staying in a bungalow 100m from where their bodies were found on Sai Ree beach and had been at a party there on Sunday night, according to Sky sources.

Reporter Mark Stone said police have cordoned off the beach and shut down ferry routes to and from the mainland.

He said: "It was a particularly gruesome attack. Eyewitnesses have said the two victims sustained incredibly serious head wounds."

Investigators are investigating whether there was a sexual motive for the attack and have been checking CCTV footage from nearby restaurants, hotels and shops for clues.

Footage from the scene showed shocked tourists and locals gathered behind a cordon on the beach on Monday while dozens of police carried out investigations.

The victims' bodies were removed from the beach in blue body bags.

The UK Foreign Office confirmed the dead woman was from Great Yarmouth, Norfolk, while the man was from Jersey, in the Channel Islands. The office sent a representative to the island to assist with the investigation.

According to the Lonely Planet travel guides, Koh Tao welcomes thousands of visitors who "come to worship the turquoise waters offshore".

The guides say its turquoise coral, sharks and rays attract divers, while hikers enjoy jungle walks and the bar scene "rages on until dawn".

Tourism in Thailand has been badly affected by the country's deep political crisis and the introduction of martial law.