documents and writings available on the topic. Much of the information important to the topic was destroyed, lost and largely covered up. Much of the information held by the United States had been kept classified until recent times. The first notable non-governmental inquiry into the topic was conducted by journalists Peter Williams and David Wallace. They brought to light the experimentation and attacks committed by Japanese Unit 731 and the plans devised by general Shirō Ishii. They also spoke of alleged coverup of the Japanese war crimes. The works of these men brought exposure to the western world. Historian Sheldon Harris later furthered this work and brought even more exposure onto the subject, with in-depth rigour and evaluation of the subject. Harris collected research from people who had direct knowledge and experience with the events. Additionally, he brought to light the different units involved in the biological weapons program such as Units 731, 1644, 100 and more. See also Japanese war crimes References Japanese war crimes 1940 in Japan 1940 in China Biological warfare Japanese biological weapons program