The Philippine Coast Guard collects seawater samples from an oil spill off Naujan on March 2. (Photo: AFP)

Hanoi - Authorities in the Philippines are exerting efforts to find and secure a sunken tanker loaded with 800,000 litres of industrial fuel oil that has started to leak into waters.

The tanker, Princess Empress, was travelling from Bataan province, near Manila capital city, to the central province of Iloilo on February 28 when it faced engine trouble and sank in rough seas.

The Philippine Coast Guard initially reported that a spillage spotted in the sea was diesel fuel from the stricken vessel’s engines and not the ship’s cargo of industrial oil.

But the Coast Guard said on March 2 that tests of water samples showed that some of the industrial oil had leaked into the sea off Naujan city.

The spill had spread over 24 sq.km by March 1, the Coast Guard said previously. It is not known how much diesel fuel and how much of the industrial fuel oil cargo is in the water.