Page 52 - Unit 731

his arrival date in Tokyo.
Appearance of Ishii

The US Army found Shirō Ishii on 5 February 1946, and A. T. Thompson began his interrogation.
On 16 February, the Secret Intelligence Service and military sent Civil Intelligence Section a list of those connected to Shirō Ishii, including Kanji
Ishiwara, Masaji Kitano, Ryoichi Naito, Enryo Houjyo, Nishimura Eiji, Hisato Yoshimura, and nineteen others. The ongoing interrogation was recorded;
however, there was, as yet, no substantiation of the use of living humans in experimentation.
According to US Army records of 11 March 1946: ‘Shirō Ishii needed to report his address to the US Army when he returned home to Chiba
prefecture. The Intelligence Agency planned to interrogate Ishii, and he needed to be ready for interrogation at any time’. 9
According to US Army records of 16 March: ‘Shirō Ishii did not report to the US Army. He made up an excuse of illness to stay in Tokyo. Shirō Ishii’s
wife, Ishii Kiyoko, said Shirō Ishii would go back to Chiba prefecture and report to the US Army when he arrived’. 10
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The US Army record of 1 April states: ‘Shirō Ishii did not report his address in Chiba prefecture to the US Army. Six months after the surrender of
Japan, the US Army had found Shirō Ishii and Masaji Kitano, a breakthrough in uncovering the secrets of Unit 731, human experimentation, and biological
warfare.

Secret Investigation and Interrogation by the US Army
The US Department of Defense led the investigation into Japanese biological warfare. With the assistance of the Supreme Commander for the Allied
Powers, the US Army carried out a series of secret investigations from the end of the Second World War through late 1948. Murray Sanders, A. T.
Thompson, Norbert Fell, and Edwin V. Hill from the Fort Detrick, Maryland, military base wrote concluding reports regarding their investigations of the
Japanese officers.
Investigation by Murray Sanders

Prior to the end of the war, the US Army had learned of biological warfare carried out by Japanese troops in Hunan and Zhejiang, China. After war’s end,
the US treated it as a highly confidential matter and tried every method to obtain access to documentation. Murray Sanders, a biological warfare expert
from the Detrick military base, arrived in Japan soon after the surrender and conducted an investigation from September to October 1945. Sanders
interrogated the Japanese Army Hospital School, Imperial Japanese Army General Staff Office, members of the Ministry of War of Japan and important
members including Ryoichi Naito, Junichi Kaneko, and Tomohisa Masuda. Unfortunately, Sanders failed to find the escapee, Shirō Ishii. On 1 November
1946, Sanders completed his ‘Japanese Intelligence Information Investigation Report—Biological Warfare’, often known as ‘The Sanders Report’.
‘The Sanders Report’ covered research areas, operation system, duties, Unit 731 members, organisations, production records of vaccines, and bacteria.
A map of Pingfang area and design plans of bacteria bombs were included. Sanders received important information about the core mission of Unit 731
from the Japanese interviewees that the Japanese had made tremendous efforts to develop the biological experiments into practical weapons, at least eight
kinds of special bombs able to disperse large quantities of bacteria were tested experimentally. The most advanced weapon was the UJ150 bomb, of which
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over 2,000 were tested. The tests were carried out by static blasting and air bombing in the Pingfang area, using more than 4,000 bombs. The report
recorded details of the experiment, statistics, the model number of bombs, and field human experimentation. These details assisted the US Army
investigation of biological warfare, human experimentation, and biological weapons of Unit 731.
Investigation by A. T. Thompson
Col. A. T. Thompson, a biological warfare expert from the Detrick base, arrived in Japan to investigate Unit 731 after Sanders departed. A military
veterinarian, Col. Thompson interrogated members of Unit 731, including Ishii and Kitano, and members of Unit 100 (Thompson committed suicide in
1948 for unknown reasons).
First Meeting with Investigator
On 5 February 1946, Thompson visited the home of Shirō Ishii. The interrogation began and ended in a cordial atmosphere. The following narrative is an
excerpt of the report:

Q: You did no BW work except at the Army Medical College and at Heibo?
A: BW work was done only at Heibo. Only general preventive medical science was conducted at the Army Medical College.
Q: Was any work done at the Kyoto Imperial University?
A: The professor there did not like that kind of work, so none was undertaken.
Q: The research work was limited to Heibo institute?
A: Only at Heibo. A lot of men in my unit and others who do not know anything about it have been spreading rumours to the effect that some secret work has been carried on in BW and they have
gone as far as saying an attack with BW was planned by my unit and that a lot of bacteria were being produced, large quantities of bombs manufactured and airplanes being gathered for that
purpose. I want you to have a clear understanding that this is false.
Q: In other words, no work was conducted on BW except at the Heibo institute?
A: That is correct
Q: Did you except the enemy to use BW?
A: In my opinion, some countries might.
Q: Which countries did you expect to use it?
A: Soviet Union and China. They had used it previously and I expected them to use it again.
Q: What did expect from the United States in the field of BW?
A: I did not think the United States would use BW.
Q: Why?
A: I believed since the United States had money and materials, they would use more scientific method of warfare.
Q: Do you think BW is practical?
A: You have to have much money and materials to create conditions favourable to BW.
Q: Do you think BW is something that nations will have to contend with in the future?
A: In a winning war, there is no necessity for using BW and in a losing war, there is not the opportunity to use BW effectively. You need a lot of men, money and materials to conduct research into
BW. There is little data on the effectiveness of BW as a weapon. I do not know whether BW can be used effectively on a large scale. It might be effective on a small scale.
Q: Do you mean sabotage?
A: It might be effective in such methods of sabotage as dropping bacteria into wells.
Q: It might be effective under those conditions?
A: I believe such methods could be controlled by my methods of water purification. I heard over the radio that Russia had completed its preparations for BW and it frightened me, but I did not know
whether it was actual fact or just was printed in ‘Red Star’ or some other newspaper as a ‘scare’. I do not know how far they have advanced in BW and have wondered what they would use if they
attacked with BW.
Q: What bacteria do you think the Russians might use?
A: Tularaemia, typhus fever, cholera, anthrax, pest.
Q: What makes you believe that the Russians would use these organisms?
A: I heard reports from people returned from Russia that the Russians had been using these organisms in their preparation for BW.