Chalong Police were called to the home at at 12:30pm, said Pol Lt Col Patiwat Yodkhawn.
Officer arrived with rescue workers to find the body of 65-year-old man beside the pool at the back of the house.
“There were no signs of foul play, injury or assault,” Pol Lt Col Patiwat said.
One of the victim’s friends, who police declined to identify, said the man had been swimming alone for about one hour before his condition was noticed.
“I came out and saw him unconscious in the pool,” said the friend. “I pulled him out of the pool and administered CPR while others called police for help.”
The man’s body was taken to Vachira Hospital for doctors to confirm the cause of death.
“At this stage we believe that the victim suffered from leg cramp and drowned, but we will wait for doctors to confirm the cause of death,” Pol Lt Col Patiwat said.
The Phuket News is withholding the man’s name until it has been confirmed that his family have been notified.