Sydney:
Navy exercises off Papua New Guinea have uncovered what is believed to be the wreck of a World War II submarine in a notorious wartime harbour, officials said today.
The wreck was discovered during joint Australia and New Zealand navy training in Simpson Harbour - a massive deepwater cavern created by an ancient volcanic eruption at the eastern tip of New Britain Island.
Simpson Harbour was the Japanese navy's principal anchorage in the South Pacific during WW-II, with dozens of ships sunk there by Allied bombing raids.
Australian defence authorities said the wreck, believed to be a submarine, was found off Rabaul yesterday.
Rabaul was Japan's forward base for its mainland campaigns in Papua New Guinea including the critical Kokoda Track battles with Allied forces, and defence said the harbour was "known for submarine operations" during the war.
"As with any wreck discoveries, immediate identification is not possible and work will continue over the coming days to identify both the type and the nationality of the vessel," it said of the undersea find.
"Authorities from the USA, Japan, PNG and New Zealand have been informed of the discovery."
Then the separate Dutch and Australian territories of Papua, New Guinea and Dutch New Guinea, Papua New Guinea was strategically important in the war due to its proximity to Australia and large land area, where bases could be built.