Data on nuclear power plant safety inspections have been posted on the Internet, apparently leaked through the Winny file-swapping program on a virus-infected personal computer of an employee at the Nuclear and Industrial Safety Agency, the agency said Friday.

The leaked data include reports on inspections between 2000 and 2002, and information on the operational status of nuclear plants in Fukui, Niigata, Shizuoka and Kagoshima prefectures, according to the agency, a unit under the Ministry of Economy, Trade and Industry.

No information on the security surrounding nuclear material or personal data has been posted on the Internet, the agency said.

An agency employee in charge of inspections of nuclear plants had taken the data home and worked on his personal computer when the data were leaked, it said.

The personal computer is suspected to have been infected with a virus and the data are thought to have been leaked through Winny peer-to-peer file-sharing software, which was installed in the PC.

In June, a large volume of classified technical data on seven nuclear power plants were discovered posted on the Internet. That information was also taken through the Winny software on the personal computer of an employee at a plant-maintenance company.