The British yachtsman on a sailing holiday in southern Thailand who was beaten to death and thrown overboard was attacked by pirates who demanded his credit cards and computer.

Malcolm Robertson, 64, from St Leonards, East Sussex, was sailing in his 300,000 pounds sterling 44 Bruce Roberts cutter Mr Bean with his wife Linda, off Satun near the Thai-Malaysian border. Thai police say three pirates clambered aboard and overpowered the couple, tying Linda up and locking her in the cabin for 10 hours.

When she got out she found blood on deck but no sign of her husband. She waved down a passing vessel and the authorities were alerted.

It has been alleged that the killers either bludgeoned him to death with a hammer or slit his throat as he shouted for help.

Thai police said three migrant workers from Burma had confessed.

Mr Robertson, a retired bakery chain owner, had circumnavigated the globe with his wife.