Japan had long denied it engaged in germ warfare in China during World War II. But the situation took a shift in August 2002 when 180 Chinese victims sought compensation from the Japanese government.

Although they were to face disappointment when their petition was rejected by the Tokyo District Court, Judge Koji Iwata declared for the first time "The deployment of biological weapons (in China in the 1930s and 1940s) was a strategic part of Japan's war plans and was carried out under orders from the central command of the army."

The Japanese army's so-called "Epidemic Prevention and Water-Supply Unit" is better known as Unit 731. It was established in 1936 under an imperial edict issued by Emperor Hirohito (1901-1989) which established the basis for the atrocities it would go on to commit. Judge Iwata said its "main objective was to research, develop and manufacture biological weapons."

From 1936 to 1945, the notorious Unit 731 conducted biological experiments on live human subjects as it developed its biological weapons. Many Chinese people lost their lives subjected to these cruel experiments.

Many people have come from around the world to the site of the Unit 731 headquarters some 20 kilometers south of Harbin, capital of northeast China's Heilongjiang Province. They wish to see the evidence of the Japanese army's guilt with their own eyes. However there has been disappointment at the lack of tangible evidence to be seen on the spot.

With its defeat in 1945, the retreating Japanese army blew up all the buildings on the site except the main office. This now houses the Unit 731 Criminal Evidence Museum.

"In fact, Unit 731 constructed extensive underground facilities for their human experiments. They did not have time to destroy these when they pulled out. So a tremendous amount of evidence must have been buried deep underground," said Wang Peng, the museum's curator.

According to local people, those underground structures had caused them a lot of trouble. For instance, when excavating for house foundations, they have often come across hidden openings going down to fathomless depths.

Since 1945 the local government has never carried out a comprehensive investigation into the ruins of the buildings and equipment left by Unit 731," said Wang Peng. "To make matters worse, over the past few decades people were moving into the area of the historic site. This continued until 2000 when all the residents here were relocated and a small-scale excavation was launched.

The 2000 dig exposed the No.7 prison and a germ warfare laboratory where prisoners were subjected to bacteriological experiments. In the absence of good maintenance due to a shortage of funds, all the remains that were unearthed have fallen prey to erosion, weathering, and frost damage even though they were under provincial-level protection.

"Taking the post-dig costs of preserving the relics into account, some experts say that no less than 30 million yuan (about US$3.75 million) would be needed to launch a full-scale excavation at the Unit 731 site. The state's current annual budgetary appropriation of 270,000 yuan (about US$33,750) is just a drop in the ocean. Given the museum's inadequate ticket earnings and the lack of any non-governmental capital it's proving extremely difficult to get the excavation project started," said Wang.

Thus the museum has often found itself in a difficult position for many of the Japanese atrocities admitted by former members of Unit 731 cannot be confirmed by tangible evidence at the site. For instance, on August 11, 1945, after blowing up the buildings at the Unit 731 headquarters site, the Japanese army shot dead over 400 prisoners on the experimental list. They poured gasoline on the corpses and burned them in eight pits. Some remains were thrown into the Songhua River.

Wang said, "Many former Unit 731 members have spoken of this cold-blooded massacre, but none of the victims' remains have been found, nor will they be without a full-scale excavation."

Another problem troubling Wang is that the former personnel of Unit 731 are now dying off themselves. They are important witnesses with information on the Japanese army's brutality. In 2000, excavations to the northwest of the No.7 prison uncovered what was at first thought to have been the boiler room. However, some former Unit 731 personnel returned to the spot by invitation on two occasions in 2001. They all consistently verified that what had been unearthed was in fact a "dissecting room". One of the returnees admitted he had personally vivisected five Chinese prisoners in that place.

Another former member of Unit 731 told Wang Peng, "Eight of my former colleagues in Unit 731 who are now confined to their sickbeds, hope to see you in Japan. They want to tell you of the tormenting secrets buried in their hearts."

According to Wang, six or seven years ago, around 700 to 800 former Unit 731 members were still alive. However in recent years, visiting Japanese delegations have saying that more and more of them are now dying.

Many former Unit 731 members prefer not to reveal the truth about what they were involved in until one or two months before their own deaths.

"So it's necessary for us to keep in close touch with them and help dispel their misgivings," said Wang.

"The physical remains to be found at the Unit 731 site represent material evidence. Those former Unit 731 members who are still alive are witnesses," Wang said. "Our job is to take account of what both the material evidence and the witnesses have to tell us. This dialogue is becoming more urgent than ever before."

(China.org.cn by Shao Da, October 4, 2004)