As reported on the other thread, I located the online English edition of Asahi Shimbun (
http://www.asahi.com/english/) and used its search feature to search for "Leica." No hits.
This and the other failed confirmation attempts may not prove that the rumor is false (it's impossible to prove a negatively-stated proposition) but do show that at this point, it can't be confirmed independently with broadly available information.
This is how the Bermuda Triangle stories got started: one author told some stories without saying where he got them, then some other authors repeated them based on what
he said, and then others based on what
they said, and pretty soon everybody figures they must be true because "there have been so many reports." Yet if you pick one of the stories and trace it back to its original author, then try to confirm it in primary-source materials that would have been available to him, you can't find anything.