Stalin nearly went to war with the USA after we smuggled Japanese scientists and documentation from that camp.
“The MenBehind the Sun.” Is the only movie I think was made about it. Not for the weak of heart. Available on YouTube.
General MacArthur decided that Japanese officials involved with Unit 731 would not be tried for war crimes...US wanted data from Japanese...I think General MacArthur did many good things...But, in this case...
https://en.wikipedia.org/wiki/American_cover-up_of_Japanese_war_crimes
Soviets did put some Japanese on trial for Unit 731...However, nobody was sentenced to death...Soviets sent those Japanese prisoners back to Japan by 1956...Soviets also probably got data from Unit 731...
https://en.wikipedia.org/wiki/Khabarovsk_war_crimes_trials