Days before the 81st anniversary of Japan’s unconditional surrender that marked the end of World War II, the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, Heilongjiang province, released newly examined evidence on Wednesday documenting Japan’s atrocities during the Chinese People’s War of Resistance Against Japanese Aggression (1931-45).
The evidence consists of registration files for the Hailar branch of the Imperial Japanese Army’s Unit 731 and testimonies from medical soldier Hitoshi Tanizaki, further exposing the full operation of the Japanese army’s biological warfare crimes during the war.
The branch, also known as Unit 543, maintained a stable personnel count of around 160 and was a crucial part of Unit 731’s biological warfare crimes.
Previous evidence suggests that Unit 543 collaborated with Units 731, 100 and 516 to conduct large-scale human gas experiments in the Inner Mongolia autonomous region during the war, according to the museum.
The archives comprise 185 pages, documenting the names, ranks, enlistment dates, duties, transfers, and post-war information of 156 members of Unit 543, with the majority including medical officers, medical, and ordinary soldiers, as well as a few technical staffers and civilian employees.
Jin Shicheng, director of the museum’s education and publicity department, highlighted two significant findings from the research.
“The archives clarify the personnel recruitment and transfer system between Unit 731’s headquarters and the Hailar branch,” said Jin. “The Japanese army mainly recruited personnel under the guise of regular infantry units such as Units 97, 177 and 201. After three months of training at Unit 731’s headquarters, they were assigned to the Hailar branch.”
“The deceptive recruitment method was primarily aimed at concealing Unit 731’s covert criminal activities, such as human experimentation,” said Jin.
The archives also confirm the continuity of investigations into the Japanese army’s biological warfare crimes after the war.
“Out of the 156 individuals, 145 were captured by Soviet forces and detained in the Soviet Union, with four undergoing trials in Khabarovsk between April and September 1950,” said Jin. “It confirms that the Soviet investigation and judicial accountability for Japan’s biological warfare crimes continued even after the public trials in 1949.
“The newly released archives, along with previous testimonies from former unit members, form a complete chain of evidence,” he said. “The official documents expose the facade used by the Japanese army to conceal crimes against humanity, further confirming Japan’s state-sponsored biological warfare crimes, significantly contributing to the study of Unit 731’s war crimes and the history of post-war trials.”
Along with the archives, a 70-minute video of testimonies from Tanizaki was also released.
In the video, which was collected during an evidence-gathering trip to Japan by the museum in 2016, Tanizaki detailed his involvement in field rat capture and bacterial cultivation, providing valuable supplementary information to existing research.
Tanizaki joined the Hailar branch as a medical soldier in April 1944.
After three months of training in bacterial cultivation techniques, he mastered practical skills such as culture medium preparation, apparatus classification, and incubation.
According to Tanizaki, the branch had clearly defined roles, with departments responsible for bacterial cultivation, water toxicity testing, and material management, showcasing the Hailar branch’s comprehensive preparation for biological warfare as an extension of Unit 731.
Tanizaki also described their duties in document handling and laboratory rat management.
They were responsible for daily statistics on the survival and breeding of wild rats and supplying laboratory rats to Unit 731’s headquarters, mainly replenished through field captures, illustrating the execution chain of biological warfare support.
Notably, Tanizaki mentioned that after Japan’s defeat, chemical bombs were buried in China, offering oral evidence for the investigation into Japan’s abandoned chemical weapons.
“The testimony directly corroborates the abandonment of chemical weapons by the Japanese army in China upon their defeat, explaining the historical roots of post-war chemical weapon hazards,” said Jin.
