CANBERRA, Australia (AP) -- A wreck found under water in a Papua New Guinea harbor likely was a Japanese midget submarine from World War II, a historian said Friday.
Australian and New Zealand warships found it while working in the area to clear WWII-era explosives Thursday. Simpson Harbor is in the town of Rabaul, which was a major Japanese military base on the northeast coast of the South Pacific nation.
New Zealand Navy Lt. Commander Matthew Ray told Australian Broadcasting Corp. radio the find was initially identified as "a 20-meter (66-feet) long solid, manmade object." Closer inspection confirmed it was a submarine, although its nationality was not yet known, he said.
The only submarines involved in fighting around Rabaul were U.S. and Japanese, and both sides have accounted for most, if not all, of their subs in the area, said Gary Oakley, a Australian War Memorial curator and a former submariner.
As Rabaul was Japan's major base in the Southwest Pacific for most of the war, most of the submarines in the harbor had been Japanese. Previously known submarine wrecks in the harbor were also Japanese, he said.
"My best guess would be it's a Japanese midget submarine. It doesn't look big enough to be an ocean-going ... submarine," Oakley said after examining indistinct images of the wreck released by the Australian Defense Department.
One- and two-man Japanese midget submarines were transported by ship or larger submarines and used covertly to infiltrate enemy targets including Pearl Harbor in Hawaii and Sydney Harbor.
Such a submarine could have been destroyed by an American air raid or naval bombardment or even scuttled by the Japanese toward the end of the war, Oakley said.
Ray said underwater remote-controlled vehicles with cameras will be used to try to identify the wreck.
The Japanese government had no immediate comment, pending the outcome of the Australian investigation.
Oakley said it could be the first Australian submarine lost in World War I, although that submarine, AE1, was thought to have sunk in another harbor 12 miles (20 kilometers) away.
AE1 became the first Australian naval loss of the war when it sank on Sept. 15, 1914, with the loss of 35 lives. Rabaul was then the capital of the German New Guineau colony, which was quickly lost to the British.