Police believe Song Tae Khy, 22, drowned while swimming with his friends on Friday.
The spot, known as Grand Canyon Hang Dong, is a popular tourist destination.
Pol Captain Chakrapad Songmoon, an investigator at the Hang Dong police station, said police rushed to the lake and deployed divers in a bid to locate the tourist's body on Friday itself.
"But the water was over 40 metres deep. One of the four divers bled from the ears and the operation had to be suspended. We decided to wait till the body floated up," he said.
Police have already contacted the victim's family and the South Korean Consulate about the case.