I have no sources on the US poaching specific scientists, yet I can answer with reference to the US gathering Japanese biological weapons research after the war. In the leadup to the Tokyo War Crime Trials of 1946-1948, American prosectors cut a deal with members of the Japanese Biological Weapons program (Unit 731), offering immunity from prosecution in exchange for experimental data. I won’t go into forensic detail on the experiments of Unit 731, but they were involved the development of biological weapons, and deadly tests on living human subjects. Throughout WWII, the Biological Weapons Unit, under the command of Ishii Shiro, attempted to create weapons of mass destruction for use against China, and potentially the Soviet Union and the Allies as well (though these never developed into useful battlefield weapons, and it has been suggested the Japanese may have killed more of their own troops when they deployed weapons in China). By the end of 1947, the US had completed two reports on the Japanese BW program: the Fell Report and the Hill and Victor Report. The latter of these outlined the reasons fro granting immunity to the Japanese scientists and stressed the ‘value’ of their research: “Such information could not be obtained in our own laboratories because of scruples attached to human experimentation. These data were secured with a total outlay of $250,000... a mere pittance compared with the actual cost of the studies.” (Tsuenichi, p. 204). In the 1980s, Lt Col Murray Sanders, one of the American BW experts, admitted that granted immunity from prosecution in exchange for information, claiming to have had the permission of General Douglas MacArthur.

As a result of this, Ishii and other leaders of 731 were never prosecuted at Tokyo, despite their complicity in the deaths of thousands of civilians in the most abject conditions. However, the United States was not the only power to try and benefit from this research: after the invasion of Manchuria in 1945, the Soviets took hundreds of thousands of Japanese POWs in Manchuria, including some scientists at 731. Ken Alibek, a former Soviet BW specialist, has claimed the research gathered was taken to Moscow for study, and a new BW research unit was apparently constructed at Ekaterinberg using “drawings and knowledge gained from the Japanese”. ( Yudin, p. 61).

In summary, the US granted immunity to Japan’s biological warfare unit in exchange for experimental data, whilst the USSR used information from Japanese POWs in their own BW program.

(Apologies for formatting, I’m currently on mobile).

Sources:

Boris Yudin, ‘Research on Humans at the Khabarovsk War Trial’ (2010).

Tsuneishi Keiichi, ‘Reasons for the Failure to Prosecute Unit 732 and its Significance’ (2010).

Valentyna Polunina, ‘The Khabarovsk Trial: The Soviet Riposte to the Tokyo Tribunal’ (2016).