Allies intelligence

Both arguments were flawed, of course, and Allied Intelligence later showed that the 14 ton V2 rocket bomb was in fact powered with liquid propellant, was guided using gyroscopes, and did indeed carry one ton of explosive. And on the 3rd September 1944 the first V2 fell on London. Some firework ... 

Shama, G. Reinarz, J. 2002, Allied intelligence reports on wartime German penicillin research and production , Historical Studies in the Physical and Biological Sciences, 33 (2), 347-67. 

After the war. Allied intelligence attempted to establish the extent to which German scientists had conducted chemical warfare experiments on camp inmates. From early on, investigators expressed serious doubts whether the regime would have agreed to the allocation of resources and personnel during the war for the mass production of a novel agent which... 

As work proceeded at Los Alamos and elsewhere in America, Allied intelligence agencies had been following the atomic weapons projects underway in both Germany and Japan. In Japan the project was headed by Yoshio Nishina, who had studied under nuclear physicist Niels Bohr in Denmark and had set up the Riken Institute for Physical and Chemical Research in the Japanese capital of Tokyo. Nishina built two cyclotrons at the Riken Institute. Another key scientist was Ryokichi Sagane, who had studied under Emeset O. Lawrence at the University of California at Berkeley. 

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