The Royal Thai Navy has insisted that the abandoned ship, which sunk off the coast of Nakhon Si Thammarat as it was being towed to shore on Saturday, is not a hazard to maritime traffic.
The navy said the ship poses no risk to the environment, saying the amount of oil leaking out of the wreckage was not significant and is expected to dissipate in a few days.
The chief of the Second Naval Area, V Adm Sunthorn Khamklai, said the abandoned vessel, which was first seen adrift near Chevron's offshore oil rigs some 100 nautical miles (185 kilometres) off the Songkhla coastline, is now completely underwater.
"Buoys have been placed in the area to warn local traffic of the wreckage," he said.
As for the oil leaking out of the ship, V Adm Sunthorn said a survey by the Marine Department determined that it will clear up on their own without causing any damage to the local environment.
The abandoned ship is believed to be the Fin Shui Yuan 2, a 56-metre Chinese cargo ship that was last seen in the national ship automatic identification system (AIS) in 2020.
No crew or cargo were found on board, and all documents which may shed light on the ship's origins were also missing.
The damaged ship was sunk by rough seas about 28 nautical miles off the coast of Nakhon Si Thammarat while being towed to shore on Saturday night for further inspection.
The Thai Maritime Enforcement Command Centre (Thai-MECC) said on Monday the navy was monitoring oil leaks from the ship and planned to launch a clean-up if the leak proves to be worse than initially thought.
Thai-MECC said the navy and the Marine Department are discussing the possibility of salvaging the ship's wreckage to facilitate their investigation on the vessel's origin.