The report quoted sources in the Japanese government, who have said that Olmert briefed Japan's Prime Minister Yasuo Fukuda on the attack during a meeting in Tokyo on February 27.
The Japanese paper noted that this was apparently the first time that the intended target had been disclosed to the head of a foreign government.
Israel has officially acknowledged that it carried out the September 6, 2007 attack, but failed to identify the strike's target.
According to the sources, Olmert told Fukuda that the site was a nuclear-related facility that was under construction with know-how and assistance from North Korean technicians dispatched by Pyongyang.
The sources added that Olmert said Israel remains concerned about the issue of nuclear proliferation by North Korea and seeks greater information sharing with Tokyo through expanded dialogue on the issue.
According to the report, Japanese government officials expressed differing views on how to interpret Olmert's statement.
"While we cannot confirm the facts, the fact that such an assertion was made at an official occasion such as a summit meeting is significant, making it highly credible," said one high-ranking Foreign Ministry official.
Another Foreign Ministry official pointed out, however, that the Israeli leader "may have only presented facts that were favorable for the Israeli side."