World War II ship that sank with nearly 1,000 on board found after 80 years

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.

They had been captured a few months earlier by Japanese forces in the fall of the coastal township of Rabaul in Papua New Guinea.

"At long last, the resting place of the lost souls of the Montevideo Maru has been found," Prime Minister Anthony Albanese said.

"Among the 1,060 prisoners on board were 850 Australian service members –- their lives cut short," he said on social media.

"We hope today's news brings a measure of comfort to loved ones who have kept a long vigil."

After five years of planning, explorers began searching for the wreck on April 6 in the South China Sea, northwest of the Philippines' main island of Luzon.

They made a positive sighting just 12 days later using high-tech equipment, including an autonomous underwater vehicle equipped with sonar.

"When we saw those images it was the moment of a lifetime, very exciting," Captain Roger Turner, technical director of the expedition, told AFP by phone from aboard the Fugro Equator survey vessel.

The ship had split into two sections, with the bow and stern lying about 500 metres apart on the seabed, he said.

"We think that she was struck by two torpedoes. The first one was what caused her to sink, the second one actually blew off a part of the accommodation."

The wreckage will remain undisturbed on the sea floor, where it lies at a greater depth than the Titanic, out of respect for the families of those who perished, the foundation said. No artefacts or human remains are to be removed.

"We're very conscious that it is a grave, it is a war grave for some 1,100 people -- both our Allied military and civilians but also the Japanese crew and guards," Turner said.

"It is being treated with appropriate respect."

Andrea Williams, an Australian whose grandfather and great-uncle were civilian internees who perished on the ship, was also with the team that found it.

"It was very emotional but it is also a very proud moment to have been able to find the wreck," she told AFP.

"The relatives have often said: 'Will the Montevideo Maru ever be found?'," Williams said.

Locating the vessel was "hugely comforting" to the perished prisoners' relatives, many of whom had contacted her after the news broke, she said.

Australia's Chief of Army Lieutenant General Simon Stuart said finding the wreck had ended 81 years of uncertainty for the loved ones of those lost.

"A loss like this reaches down through the decades and reminds us all of the human cost of conflict," he said. Australia's military had assisted in the search.

Those who perished aboard the Montevideo Maru included 33 crew from the Norwegian freighter the Herstein and about 20 Japanese guards and crew, the Silentworld Foundation said.

Other nations affected by the sinking included Britain, Denmark, Estonia, Finland, Ireland, the Netherlands, New Zealand, Solomon Islands, Sweden and the United States, it said.