The naked bodies of two British tourists have been found on a Thai beach, sparking a murder probe on the popular resort island of Koh Tao.

The man and woman, both aged 24, were found stripped with several wounds to their bodies close to a beachside bungalow on the island, a diving hotspot near Koh Phangan in the Gulf of Thailand, police said.

The BBC named the deceased as David Miller, from Jersey, and Hannah Witheridge, from Norfolk.

Their bodies were found close to where a beach party had been held the night before, and both had sustained horrific head wounds.

Hannah Witheridge, from Norfolk, was found dead on the beach. ( Facebook )

It has been reported police also believe the woman was raped.

"They were murdered and found naked on the beach. Police were informed at 6:30am," local police official Jakkrapan Kaewkhao said.

"Their bodies were found 30 metres from the bungalow."

Police were searching for witnesses and were yet to identify a suspect or motive.

Mr Miller and Ms Witheridge arrived in Thailand on August 25.

An employee at the budget seaside resort where the pair were staying said the bodies were found behind a set of large rocks on the beach.

"It was the first time this has happened on the island. I have never seen anything like this," the staff member said.

Quiet island popular with tourists, divers

Koh Tao is popular with tourists but draws fewer travellers than the neighbouring Koh Phangan, home to the hedonistic "full moon" party.

Access is by boat only, and the island is a popular destination for novice scuba divers.

A spokesperson from Seatran Discovery ferries, which sails to the island, said police were checking the identity of all passengers leaving the island yesterday, but ferry services would resume as normal today.

Koh Tao has a permanent population of about 2,000 people. Its name means "Turtle Island" in Thai, and the island is noted for its turtle-like shape and as an important breeding ground for hawksbill and green turtles.

Thailand's lucrative tourism industry has been battered in recent months after a prolonged political crisis ended a coup that saw the army impose a curfew and strict martial law.

Although the curfew was swiftly lifted from key tourist hotspots, visitor numbers are yet to rebound.

Thailand's military leaders have vowed to clean up the kingdom's tourist resorts after complaints of scams, assaults and even police extortion.

The British foreign office says it is urgently seeking information from local authorities.

ABC/wires