The dead man, Sebastian Wolff, 22, and his friend, Florian Zehentmair, had been holidaying at the Barisa Bungalows in Khao Lak.
Police say at least one witness saw the men fight and are holding Mr Zehentmair, 19, who denies any part in his friend's death.
Mr Zehentmair has not given an account of the events leading up to the death. He says he cannot remember because he had had too much to drink.
Police say they have a witness who saw the two Germans arguing and fighting late at night, on the beach about 200 metres from their accommodation.
The argument began when Mr Wolff went to kiss a Thai man, the superintendent of Thai Muang police station, Police Colonel Kullathorn Chaladphat, told Phuketwan.
Mr Wolff's body has been taken to Thai Muang Hospital so doctors can determine the cause of death.
Colonel Kullathorn said that Mr Wolff may have struck his head on a rock on the beach when he fell.
The body was found on Wednesday morning by people out walking, the officer said. Mr Wolff , a tall man, was wearing a yellow shirt and black shorts.
Not far away police found Mr Zehentmair in a deep sleep, apparently induced by excessive consumption of alcohol.
Police woke up Mr Zehentmair and showed him the body of his friend on the beach.
He is now being held at the local police station pending the autopsy result and a full statement from the witness, who remains anonymous for now.
The German pair had been staying in Khao Lak since May 12. They were due to check out on May 26.
Woah, another mystery death of a tourist. What's going on here?!
Posted by LC on May 14, 2009 19:35