In the closing months of World War II, in the Philippines, several of Japan's highest ranking imperial princes hid tons of looted gold bullion and other stolen treasure in caves and tunnels, to recover later. This was the wealth of 12 Asian countries, accumulated over thousands of years. Expert teams accompanying Japan's armed forces had systematically emptied treasuries, banks, factories, private homes, pawn shops, art galleries, and stripped ordinary people, while Japan's top gangsters looted Asia's underworld and its black economy. There were 175 ''imperial'' treasure sites hidden throughout the Philippines. When American tanks were close, the chief engineers of those vaults were given a farewell party 67 metres underground in Tunnel 8 in the mountains of Luzon, stacked with row after row of gold bars. As the evening progressed, they drank great quantities of sake, sang patriotic songs and shouted banzai (long life). At midnight, General Yamashita Tomoyuki and the princes slipped out, and dynamite charges were set off in the access tunnels, entombing the engineers. Their vaults would remain secret. The princes escaped to Tokyo by submarine, and three months later General Yamashita surrendered to American troops. Japan had lost the war militarily, but the princes made certain Japan did not lose financially. This grisly event has remained unknown until now, and the hidden treasure was brushed off as a fanciful legend of ''Yamashita's Gold''. But an eyewitness to the entombment has taken us there and given us his personal account. During the war, Ben Valmores was the young Filipino valet of a senior prince, who was in charge of closing all imperial treasure sites in the Philippines. A sometimes sentimental man, the prince spared Ben's life and led him out of Tunnel 8 just before the dynamite was detonated. Japan's looting of Asia was overseen by [then-emperor] Hirohito's brother Prince Chichibu. His organisation was codenamed kin no yuri (Golden Lily), the title of one of the emperor's poems. Other princes headed different parts of Golden Lily across the conquered territories. Eventually, Japanese sources told us that Ben's wartime master was prince Takeda Tsuneyoshi, first cousin of Hirohito and grandson of emperor Meiji. In 1998, we tested Ben with 1930s photographs of many princes, all the names removed, and he instantly identified prince Takeda, Hirohito's brother prince Chichibu and other princes. Ben said he had spent time with each of them, bringing them food, tea and cigarettes while they inventoried each treasure site. When he saw our photo of Prince Takeda, Ben froze, then began softly crooning the Japanese folk song Sakura, Sakura (Cherry Blossoms), which he said Takeda often sang to himself. In the final stages of work on a biography of Japan's imperial family titled The Yamato Dynasty, we were told that in October 1945, American intelligence agents learned where some of the Japanese loot was hidden in the Philippines, and quietly recovered billions of dollars worth of gold bullion, platinum, and loose diamonds. This information, if true, revealed the existence of an extraordinary state secret, something the United States Government kept from its own citizens for more than half a century. There was no time to include this in the biography. It had to be investigated separately. Here is some of what we have since learned: After surrendering on September 2, 1945, General Yamashita was charged with war crimes over gruesome atrocities committed in Manila under the order of an admiral, while Yamashita had ordered withdrawing troops to leave the city unharmed. During his trial, there was no mention of plundered treasure, or of looting during the war. But we now know there was a hidden agenda. Because it was not possible to torture General Yamashita physically without this becoming evident to his lawyers, members of his staff were tortured. His driver, Major Kojima Kashii, was given special attention. In charge of the torture of Major Kojima was a Filipino-American intelligence officer named Severino Garcia Santa Romana, whose friends called him Santy. He wanted the major to reveal each place where he had taken Yamashita, where bullion and other treasure was hidden for recovery after the war. Supervising Santy during the torture was Captain Edward Lansdale, later one of America's best known ''Cold Warriors''. Early that October, Kojima broke and led Lansdale and Santy to more than a dozen Golden Lily treasure vaults in the rugged country north of Manila. What they found astounded everyone from General Douglas MacArthur all the way up to the White House. After discussions with his cabinet, President Harry Truman decided to keep the recovery a state secret. Santy's ensuing recoveries greatly altered America's leverage during the Cold War. According to senior US government officials and high-ranking US Army officers, the Truman administration set this treasure aside along with Axis loot recovered in Europe, as a secret political action fund to fight communism in the Cold War. Crudely put, it would be used to bribe statesmen and military officers, and to buy elections for anti-communist political parties. The idea for a global political action fund based on war loot had originated with US secretary of war, Henry Stimson. During the war, Stimson had a brain-trust thinking hard about recovered Axis plunder, and how it should be handled after the war. Their solution was to set up what is informally called the ''Black Eagle Trust'', after the black eagle emblem of Hitler's Reichsbank in Berlin. The Black Eagle Trust was first discussed in secret during July 1944, when 44 nations met at Bretton Woods, New Hampshire, to plan the post-war economy. This was confirmed to us by a number of high-level sources, including former CIA deputy director Ray Cline, who knew about Santy's recoveries in 1945, and continued to be involved in attempts in the 1980s and 1990s to hide blocks of Japanese war loot still said to be in the vaults of banks in New York. In November 1945, General MacArthur strolled down row after row of gold bars stacked two metres tall during a tour of vaults opened by Santy. >From what was seen in these vaults alone, it was evident that over a period of years Japan had looted billions of dollars in treasure from all over Asia.Much of this plunder had reached Japan overland earlier, from China through Korea, but the rest was hidden in the Philippines, unable to be shipped to Japan by sea because of the successful US submarine blockade. According to Ray Cline and others, between 1945 and 1947 the gold bullion recovered by Santy and Lansdale was moved discreetly to 172 accounts at banks in 42 countries. There were important reasons for all this secrecy. If the recovery of this huge mass of stolen gold was known only to a trusted few, the countries and individuals that had been plundered could not lay claim to it. Truman recognised that the very existence of so much black gold, if it became public knowledge, would cause the metal's fixed price to collapse. But as long as the gold was kept hidden, prices could be maintained and currencies pegged to gold would be stable. Meanwhile, the black gold would serve as a reserve asset, bolstering the prime banks in each country, and strengthening the anti-communist governments of those nations. To hide the existence of all this treasure, Washington had to tell a number of lies. Especially lies about Japan, which had stolen most of the gold. America wanted Japan to become its anti-communist bastion in Asia, where the mainland was being overrun by communists. If American conservatives and Japanese conservatives were to ally effectively against communism, they had to begin by enlarging their financial resources for the Cold War. Above all, the source of much of this hidden wealth must never be acknowledged. Washington had to insist, starting in 1945, that Japan never stole anything, and was flat broke and bankrupt when the war ended. Here was the beginning of many terrible secrets. Because they remained ''off the books'', these enormous political action funds got into the wrong hands, where they remain to this day. We can reveal that in 1960, then vice-president Richard Nixon ''gave'' one of the biggest of these political action funds, the US$35-billion (about HK$272 billion) M-Fund, to leading members of Japan's Liberal Democratic Party (LDP). In return, he is believed to have sought their support for his presidential campaign that year. The M-Fund, now said to be worth more than US$500 billion, is still controlled by members of the LDP. Officially, we are told that Japan's wartime elite the imperial family, the zaibatsu (large industrial business conglomerates), the yakuza (Japanese mafia) and the ''good'' bureaucrats ended the war as impoverished victims of a handful of ''bad'' military zealots. We are told that Japan was badly damaged and impoverished, barely able to feed itself at war's end. In fact, Japan emerged from the war far richer than before, and with remarkably little damage, except to the homes of millions of ordinary Japanese who did not count, at least in the view of their overlords. Evidence of Golden Lily loot comes also from straightforward legal actions in America. Such simple things as the probating of the will of Santa Romana (Santy), verification of his tax records, and legal evidence of his fortune deposited in the US, Switzerland, Hong Kong and elsewhere, provide hard proof that the world is awash with clandestine bank accounts growing out of Golden Lily. Other lawsuits in the US prove that Golden Lily war loot was indeed hidden in the Philippines. Rogelio Roxas, a Filipino locksmith, found a one-tonne solid-gold Buddha and thousands of gold bars hidden in a cave near Baguio only to have it stolen from him by President Ferdinand Marcos. Roxas was subsequently tortured and died in suspicious circumstances. Some believe he was murdered. In 1996, a US Federal Court awarded his heirs a judgment of US$22 billion against the Marcos estate. As the 1951 Peace Treaty was skewed by secret deals, thousands of Japan's victims have been deprived of any compensation for their suffering. According to Article 14 of the Treaty: ''It is recognised that Japan should pay reparations to the Allied Powers for the damage and suffering caused by it during the war. Nevertheless it is also recognised that the resources of Japan are not presently sufficient.'' To reinforce the claim that Japan was broke, Article 14 noted that ''the Allied Powers waive all reparations claims of the Allied Powers and their nationals arising out of any actions taken by Japan...'' By signing the Treaty, Allied countries concurred that Japan's plunder had vanished down a rabbit hole, and all Japan's victims were out of luck. In return for going along with the Treaty, the Allies received portions of the gold bullion recovered by Santy. We have evidence from former CIA deputy director Cline that the gold bullion Santy and Lansdale recovered was secretly moved to national treasuries and prime banks in more than 42 countries, including Great Britain. We also have evidence from British archives confirming this. More than half a century later, the last battle of the Pacific War is being waged in courts in the US and Japan where surviving prisoners of war, slave labourers, comfort women and civilian victims of Japan have filed billion-dollar lawsuits to win compensation so mysteriously denied them after the war. In 1995, it was estimated that there were 700,000 victims of the war who had still received no compensation. Today, their numbers are dwindling rapidly because of age and illness. Backing them is an extraordinary coalition, including international law firms with years of experience, fighting for compensation from German industries and Swiss banks, for crimes committed and money looted during the Nazi Holocaust. Sterling and Peggy Seagrave are the authors of ''Golden Warriors''. This is an edited extract of the book's prologue. It will be published in French by Editions Michalon in November http://features.scmp.com/