Bang Kholaem police were alerted at 8.40am that the body of a man was stuck to a buoy behind the Kasikon Bank head office.
The body appeared to be a man between 30 and 40 years old and about 170 centimetres tall. The man, who was not carrying identification, was not wearing a shirt and his back was covered with a tattoo.
The body was sent to Siriraj Hospital for an autopsy.