Deep sea explorers have located the World War II shipwreck from Australia's most deadly maritime disaster, the search team announced on Saturday.

The Montevideo Maru, a Japanese transport ship, was carrying almost 1,000 Australian prisoners of war — mainly soldiers — when a US submarine crew that was not aware of the passengers torpedoed the vessel off the coast of the Philippines on July 1, 1942.

Civilians from other countries were also on board, bringing the total death toll to around 1,060.

"The discovery of the Montevideo Maru closes a terrible chapter in Australian military and maritime history," said John Mullen, director of the Silentworld Foundation which promotes maritime archeology.

"Families waited years for news of their missing loved ones, before learning of the tragic outcome of the sinking," Mullen added. "Some never fully came to accept that their loved ones were among the victims."

Discovery five years in the making

Silentworld spent five years planning the mission with the Dutch deep-sea surveying company Fugro and the Australian Department of Defense.

The search was conducted using an autonomous underwater vehicle (AUV) in the South China Sea. The team detected a positive sighting using sonar 12 days later.

The shipwreck was found on the seabed more than 4 kilometers (2.5 miles) below the surface — a greater depth than the Titanic.

It will remain undisturbed out of respect for the families of those who perished, the foundation said, and no artifacts or human remains will be removed from the seabed.

"At long last, the resting place of the lost souls of the Montevideo Maru has been found," Australian Prime Minister Anthony Albanese said in a statement on Saturday.

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