The police found the monazite stockpile during a search of properties owned by the foundation near Tokyo and in central Japan. According to science agency officials, there were no harmful levels of radioactivity at the sites. In interviews with domestic media, the president said he had imported 50 tons of monazite from Thailand about 20 years ago with the intention of selling it on to hot-spring resort operators, who strive to offer unique mixes of minerals in bath waters. The president said he had sold most of his original stock and the remaining 15 tons was securely stored. The police are investigating whether he broke nuclear-related laws by importing or storing the monazite.
Attention is also focused on the intentions of the sender of the radioactive letters.
One theory is that the warning was designed to raise fear about the North Korean capital Pyongyang's nuclear weapons programme before yesterday's historic summit between the leaders of North and South Korea.