The maid - gardener is also employed at the property - discovered her boss in the water about 9.30am and called for help.
Officers from Chalong Police Station investigated and were not able to draw conclusions about what may have caused the man's death.
An examination by doctors at Vachira Phuket Hospital in Phuket City should be able to determine whether he drowned.
The Russian was staying with his daughter who was not at the villa at the time, police said. It's not known whether the pair were tourists or residents.
Phuketwanhas the man's name but is withholding publication until relatives have been notified.