Captain Le Van Tien, deputy commander of Border Guard Squadron 1 under the Ca Mau Border Guard Command, said the unit was investigating the case involving fishing vessel LA-99095-TS.
The vessel was spotted at around 10.30 pm on September 25 while operating about 30 nautical miles east of Ganh Hao estuary in Ca Mau Province.
During an inspection, border guards found a large quantity of yellowish-brown liquid smelling of fuel stored in two tanks on the vessel's forward deck.
The vessel was captained by Nguyen Van Tu, 40, from Dong Thap Province, with four other crew members on board.
Tu was unable to provide documents proving the legal origin of the cargo. He told authorities that the vessel was carrying 40,500 litres of diesel oil, which he had bought from an unidentified vessel at sea for resale at a profit.
Border guards documented the case and escorted the vessel and crew to Border Guard Squadron 1 for further investigation.
