Loyal ShadowLands contributor stackja1945 has previously commenced a (serious) post about the leaking of information during WWII to the Japanese. Here is Pt II:
Excerpts from David Horner, Breaking the Codes.
On 1 February 1943 the U.S. Army’s Signal Intelligence Service, a forerunner of the National Security Agency, began a small, very secret program, later codenamed VENONA. The original object of the VENONA program was to examine, and possibly exploit, encrypted Soviet diplomatic communications.Victor Zaitsev 16 March 1943 came from USSR his identity only known later otherwise his travel may not have been allowed. Walter Clayton came from NZ in 1943, Clayton did not have a passport.From 1943 to 1945 Russia was Australia's wartime ally.
There is speculation that Zaitsev recruited an agent in the Australian Government. Herbert V. Evatt and his staff saw the reports that later reached Japan. About 50 percent, of the 1943 GRU USSR Army Intelligence from Washington to Moscow and Moscow to Washington messages, were read but none from any other year. In Australia Herbert V. Evatt was contemptuous of security. And John Burton’s attitude is hard to fathom. Particularly as Burton was advised concealed microphone
Deschamps to BurtonCablegram 59 MOSCOW, 20 March 1947, 5.45 p.m.
TOP SECRET To be deciphered only under instructions from the Secretary.PERSONAL for Burton.Reference your Top Secret memorandum P1 46/11/7/5 of 29th November, 1946.Search by expert has revealed a microphone behind the skirting board in the Minister's office and there is reason to suspect the existence of others and the possibility that the whole of the legation may be wired. The search is continuing and nothing is being disturbed until the installation has been located, when, with your approval, it is proposed to remove the whole apparatus. Your instructions are urgently awaited. Please treat the matter with the greatest reserve as other establishments here are also affected and we are in consequence not altogether free agents. The utmost secrecy is being maintained here. 1 Burton himself drafted a reply in his own hand on his copy of the cable. It read: 'Your 59. By all means remove apparatus. Utmost security must be maintained but you should immediately communicate warn personally Heads of Missions of NZ, UK and USA. We are meanwhile considering how protest should be made. Assume NZ Head of Mission is aware of discovery'. He subsequently crossed out that part of the second sentence from 'but' to 'USA'.[SFU : EVATT PAPERS: CABLES-MOSCOW-1943-49]