A man is expected to be charged with manslaughter following an arrest, police in Thailand said.
Police said British tourist Stephen Ashton was with a group of friends and 300 other tourists on New Year's Eve.
They were celebrating the countdown to 2013 at a pub and restaurant called the Zoom Bar when he was shot by a home-made gun at Haad Rin beach shortly after 4am.
The Bangkok Post reported that he was visiting the island with four or five friends and was staying at Pink Bungalow on Haad Rin.
More top news
Leicester City players have been celebrating their Premier League title after Spurs drew with Chelsea on Monday night.
Tonight western and northern areas will remain a little breezy with a few showers at times.
Leicester are Premier League champions after Tottenham conceded a two-goal lead in a bad-tempered 2-2 draw at Chelsea.