The body was strung up in a tree near a fish market in Phuket City's Rassada disstrict. A woman discovered the body about 3am and called police.
Captain Somchai Nubun of the Phuket City Police Station said today that the man had severe head wounds that could not have been caused by the hanging.
''We thnk he was beaten to death then his assailants decided to pretend it was a suicide,'' the captain said.
The man,aged 30-35 and 165-170 centimetres tall, was dressed only in a pair of boxers. His body was taken to Vachira Phuket Hospital in Phuket City.