
Malcolm Robertson, 64, was killed Monday evening while on a yacht with his wife near Koh Dong, an islandm west of Satun province.
Linda Robertson, his wife, told police that the attack took place while they were holidaying on a yacht.
Thai police arrested three Burmese migrant workers suspected of murdering the British man.
The alleged attackers confessed to killing Robertson after he caught them climbing onto his moored yacht in an attempt to steal an inflatable dinghy.
The trio had been working on a trawler moored near the Robertsons' yacht. Police said the victim shouted for help and they slit his throat with a knife and hit him before throwing his body overboard.