More than 900 counterfeit 10,000 yen bills with finely crafted watermarks have been found in Tokyo, Osaka and Shizuoka prefectures since the beginning of 2002, and investigators suspect an overseas criminal organization.

Seven people have been arrested for allegedly using fake 10,000 yen bills -- five Taiwanese people in Osaka, a Chinese in Tokyo who entered Japan via Hong Kong and a Japanese gangster in Shizuoka.

"It's an international, organized crime committed by a group with funds of some extent," remarked a high-ranking officer in the National Police Agency.