This was disclosed by "an outline of the research conducted by Group No. 6 of Technical Research Institute No. 9 (Noborito Institute) of the imperial ground force", a document worked out by a researcher who participated in the test at that time carried in the book titled "The truth of the above-said institute" published in Japan on July 28.

According to it, the Japanese imperialists manufactured germ weapons at the Noborito Institute, a secret weapon research institute which operated in Japan during World War II.

The Japanese imperialists selected part of the area around the Veterinary Institute under the "Government-General of Korea" in Pusan as an outdoor centre for experiment on infection in May 1944 and conducted test on the performance of germ weapon there.

As the test was conducted in top secrecy at that time, the atrocity was not known to public at all.