An autopsy performed on the body of an Indonesian man, identified only as Karsan, has determined that he drowned.Investigators, however, said it remained a mystery exactly how the 27-year-old sailor went overboard.His body was brought into T&T last Friday after having been frozen February 14.A maritime report stated Karsan was deep-sea fishing on board the vessel Rich 1, when he was discovered missing.He was subsequently seen floating in the sea and died despite efforts to resuscitate him.Sources said his body was transferred from Rich 1 to another vessel, Atlantic Rica 1, and was kept in a freezer in the hold of the ship.