Deep-sea explorers said Saturday they had located the wreck of a World War II Japanese transport ship, the Montevideo Maru, which was torpedoed off the Philippines, killing nearly 1,000 Australians aboard.

The ship — sunk on July 1, 1942, by a US submarine unaware it was carrying prisoners of war — was found at a depth of more than four kilometres (2.5 miles), said the maritime archaeology group Silentworld Foundation, which organised the mission with Dutch deep-sea survey firm Fugro.

The sinking of the Montevideo Maru was Australia’s worst-ever maritime disaster, killing an estimated 979 Australian citizens, including at least 850 troops.

Civilians from 13 other countries were also aboard, the foundation said, bringing the total number of prisoners killed to about 1,060.