Three foreign tourists were killed and one other remains missing after a packed speed boat capsized off the popular Thai holiday island of Koh Samui, a police officer said Friday.

The boat, which was carrying 32 tourists plus four crew, flipped over Thursday afternoon after it was slammed by a wave near a rocky stretch of coast off the island in the Gulf of Thailand.
The bodies of a 28-year-old British woman and a 29-year-old German woman were retrieved that afternoon, said Paiboon Omark, a district chief on the island.
On Friday morning rescue workers found the body of a third tourist, who police identified as a Hong Kong woman "in her 30s".
"Her body (was) found at 10:30am (330 GMT) some 500 metres from the accident site," Thanakorn Pattananun, the head of the island's tourist police, told AFP.
A team of 50 rescue workers in seven boats were scouring the area for a British man who is still missing, he said.
The Thai captain of the Ang Thong Explorer speedboat was detained and charged with negligence that led to deaths and injuries.
"Weather was the cause of the accident because it created high waves, but the boat was also being driven at a high speed," Apichart Boonsriro, the commander of Surat Thani provincial police, told AFP.
Four tourists -- from the UK, Australia, Germany and Romania -- were hospitalised on the island for injuries sustained during the accident, said staff at Samui hospital.
The speed boat had been taking the tourists on a day trip to a string of nearby islands and was only a few metres from a pier when it capsized.
The United Kingdom's Foreign Office confirmed the death of a British woman and said it was assisting her family.
A spokeswoman said they were aware of another British national in hospital for injuries suffered in the same incident, but did not make reference to a third citizen.
"We remain in contact with local authorities in Thailand for further information," she said.
The German Embassy in Bangkok was not available to comment.
Tourism is a key source of revenue for Thailand, but accidents involving tourists are common in a country where safety regulations are often weakly enforced.
In January a speedboat struck and instantly killed a French tourist while she was snorkelling in waters reserved for swimmers off a Thai island in Krabi province.