The secret unit was the Unit 731 in Japan in 1945 when World War II did not exist any more. This group committed extremely bad deeds. They experimented with people by using dangerous germs and chemicals in order to know what would occur. However, the majority of those who were involved in such terrible affairs never faced penalizations.
Unit 731 went to cover-up by Japan and attempted to conceal anything in connection to the war when it lost the battle. When Russian soldiers approached them the Japanese army burnt the buildings in which the experiments took place. They also murdered the captives and burnt their bodies so as to do away with all the evidence. General Shiro Ishii, the head of the team and members of his group fled back to Japan.
Surprisingly what followed was this. They had a deal with the United States which was secret. U.S. was interested in the studies of the experiments. They in turn assured Ishii and his crew that they would not be punished. During the Cold War with Russia, the U.S. had interest to apply the research in the production of germ weapons.
Due to this deal, Japan lied to people over the years that Unit 731 did not exist. Most of the group members even acquired decent government and school jobs in hospitals. Nobody ever said a word about what they had done.
The Soviet Union caught only a few people. In 1949, these folks were tried before the courts and some people were sent to jail. However, after some time they were released.
Many years elapsed before the truth was out. Others of the survivors began gossiping. Additional evidence was identified. This slow is when Japan started to say that Unit 731 did exist. But when the buildings were destroyed, the majority of the ones that did all this horrifying stuff never got punished and their secrets remained far out of reach during a long period of time.
