SYDNEY, Australia (AP) _ Japanese soldiers lost in Asian jungles during World War II cannibalized American and Australian war prisoners, native tribesmen and their own dead to survive, a historian said today.

The forthcoming book ''Unknown War Crimes - What Japanese Forces Did To Australians'' also documents a Japanese massacre of 2,500 Australian and British prisoners of war in Borneo in 1945.

That tragedy was never disclosed in Japan, and was forgotten in Australia because the six Australian soldiers who survived were too traumatized to discuss it publicly after the war.

It was overshadowed in the public consciousness by the atrocities committed by Japanese forces on POWs forced to build the Burma-Thai railway, immortalized in many memoirs and in the film ''Bridge Over The River Kwai.''

Toshi-yuki Tanaka, a professor of political science at Melbourne University, delved into war crimes archives and records of interrogations of captured Japanese soldiers to uncover long-forgotten atrocities.

His book is due to be released Nov. 20 in Tokyo by Ohtsuki. An English version is expected next year.

He found Japanese forces on Borneo slaughtered about 1,800 Australian and 700 British POWs in what is known as the Sandakan Massacre.

The Japanese were trying to move the men 160 miles through the jungle to build an air field in the town of Api. But after months of malnutrition, mistreatment and starvation, the prisoners dropped out of the march one by one and were shot by their captors.

One of the victims was an uncle of the current prime minister, Paul Keating, Tanaka said.

Tanaka also found evidence in archives of what had previously been a dark rumor in Japan - that soldiers abandoned in the jungles by the generals in Tokyo and cut off from supplies by advancing Allied troops turned to cannibalism to survive.

Japanese soldiers ate their own dead comrades. They also cannibalized American soldiers in the Philippines, and Australians and tribesmen in Papua New Guinea, the archives disclosed.

In most cases, Tanaka said, the troops ate the flesh of soldiers killed in battle and recovered from the jungle. But in some cases captured allied soldiers were killed for food.

Tanaka said he found records of at least 100 Australians eaten.