Hunt resumes for murdered yachtsman

Police earlier said they had retrieved the body from the fishermen who found it at sea, but authorities later said the corpse drifted away before they arrived at the scene.

The fishermen alerted the police after they found the body of 64-year-old Malcolm Robertson, who was beaten to death on Monday evening aboard a moored yacht near an island in southern Thailand, said marine police Col Lertchai Tinrat.

"The body was not tied to the fishing boat, so it floated away by the time rescuers arrived," he said.

The body was discovered near Koh Adang, an island off the coast of Satun province, some 600 miles south of Bangkok.

Thai police arrested and charged three fishermen from neighbouring Burma on Tuesday with murder and robbery. Police said they confessed to climbing aboard the yacht, beating Robertson with a hammer and throwing his body overboard after he found them trying to steal a dinghy attached to the yacht.

They then forced Robertson's 57-year-old wife Linda to steer the yacht to shore, police said. They fled in a raft when they saw Thai national park employees passing by in a boat.

The victim's wife escaped with minor injuries, Lertchai said.

Police said the migrants tried to steal the dinghy because they were desperate to go ashore after having been forced to work for months at sea. Police said they are still investigating the claims.

Thailand is a magnet for migrants from Cambodia, Laos and Myanmar who take menial and dangerous jobs shunned by Thais, and face exploitation in their efforts to earn a living. More than a million migrants from Burma are believed to be working in Thailand.