Now, 20 years later, the Chinese version of the 2002 book is finally reaching shelves in China. Wang Xuan, who was closely involved with the translation of the 1994 book into both Japanese and Chinese, is also the chief translator of the revised 2002 edition.

The Chinese translation of another book on the same subject, Hidden Atrocities: Japanese Germ Warfare and American Obstruction of Justice at the Tokyo Trial, is also coming out, five years after it was published and a little more than two years after the death of its author Jeanne Guillemin, a medical anthropologist and senior fellow in the Security Studies Program at Massachusetts Institute of Technology. Wang, who met Guillemin and her husband, the renowned American molecular biologist Matthew Meselson, in China in 2005, wrote the preface for the Chinese version.

"This coincidence, coupled with the sad deaths of the two scholars, both in their mid-70s, only serves to remind me of the physical and emotional toll taken of them as they wrestled with the dark truth," Wang said.

The Tokyo trial, which opened in May 1946, seven months after Japan surrendered and six months after the Nuremberg trials opened, proceeded in what Guillemin called "a radically different geopolitical context", one in which the United States, through General Douglas MacArthur, Supreme Commander for the Allied Powers, "ruled securely".

Yet it was what had been going on between the surrender and the opening of the trial that set the tone for the eventual miscarriage of justice.

In an interview with the Japan Times in 1982 Ishii's eldest daughter Harumi, then 57, said the first thing MacArthur did when he arrived in Japan on Aug 30, 1945 was to "inquire about my father".

No wonder so, according to Guillemin, even back in May 1944, MacArthur had already been informed of the discovery in a captured document of "a diagram of a Japanese Mark 7 experimental bacillus bomb, likely for anthrax and similar to munitions being developed by the United States and Britain". A US intelligence report dated Dec 15, 1944 included "a detailed map of an affiliate of Unit 731 located in Nanjing, called the Tama Unit (Unit 1644)".

In fact, two days before MacArthur arrived in Japan, Colonel Murray Sanders from Camp Detrick, Maryland, was already in Japan seeking out former Unit 731 scientists.

Sanders was to be followed by another three investigators from Camp Detrick (later Fort Detrick), the center of the US biological weapons program until 1969. These included Lieutenant Colonel Arvo Thompson, Sander's immediate successor.

Their investigations, mainly from a scientific point of view as military intelligence, were carried out simultaneously with the one done by the International Prosecution Section (IPS) of the IMTFE and the one by the Legal Section under the Supreme Commander for the Allied Powers (General MacArthur), both focused on the Japanese BW activities as war crimes.

A conflict of agendas was to erupt between what Harris dubbed "war crimes investigators" (the IPS prosecutors) and "BW/CW investigators" (Sanders and his successors). The latter, Harris wrote, "would brook no interference" from either "the issue of war criminal responsibility" or "medical or scientific ethics".