Tokyo ? A Japanese tanker spilled about 1.3 million gallons of crude oil in the eastern Indian Ocean following a collision with a cargo ship, the tanker’s operator said today.

Japan’s Kyodo news service said the spill – which would be about 31,500 barrels – may have been the largest ever involving a Japanese tanker.

The Bright Artemis tanker spilled the oil following a collision Monday with the Amar, a smaller cargo ship, Mitsui O.S.K. Lines said in a statement. It said the accident took place when the tanker maneuvered near the Amar, which was in distress about 300 miles west of India’s Nicobar islands.