AN AMERICAN tourist was allegedly stabbed to death by three Thai musicians after he refused to stop singing at a bar in a popular tourist resort, police say.

Bobby Ray Carter, 51, died after he was stabbed twice in the chest while his son Adam, 27, suffered a stab wound to his arm, during a fight with members of the house band from the Longhorn Saloon early on Wednesday at Ao Nang beach in Krabi.

Police said the three musicians were arrested at the scene and confessed to stabbing the Americans.

Carter had joined the musicians on stage for a singalong, but a row broke out when he refused to stop singing as the band took a break.

On its website, the Longhorn Saloon advertises "jam with the band" as one of its attractions, along with "good music, funfunfun and friendly staff".

"He and his son quarrelled with all three musicians because he wouldn't stop singing despite the musicians taking a break," said Lieutenant Colonel Attapong Seanjaiwuth of Krabi tourist police.

"He then demanded the money he had already given as a tip back. But the real fight broke out outside of that pub. He was stabbed twice and died while on the way to local hospital."

Thailand has come under scrutiny in recent months over its treatment of foreign tourists, who are a mainstay of the economy.

Tourists have registered a series of complaints with authorities over their treatment ranging from jet ski scams, drink spiking, robbery and assault to even police extortion.

A dozen European ambassadors recently raised the issue with local authorities on a visit to the resort island of Phuket, where a 59-year-old Australian woman was killed in June 2012 in a robbery.

Earlier in July an American man was slashed to death by a taxi driver in Bangkok after an apparent argument over the fare.

A record 22 million foreigners visited Thailand last year. Although most did not encounter any serious problems, diplomats say tougher action is needed to ensure their protection.