A sea gypsy gathering wood to make fish traps discovered the body at about 2pm and notified the Chalong police.
The corpse had long hair, was about 170-180cm tall, and dressed in a chequered shirt and long jeans with a leather belt.
“We believe the man died at least seven days ago,” said Maj Patiwat Yodkwan of the Chalong police.
The advanced stage of decomposition made it impossible for police to quickly assess whether the man was Asian or of some other ethnic descent.
“We have yet to determine cause of death and we were unable to recognize any marks on the body that might help to identify the man,” Maj Patiwat said.
“We checking all police stations across the island for missing persons reports, and the body has been taken to Vachira Hospital in Phuket Town to determine cause of death.”