On Oct. 28, what is believed to be 114 documents linked to the police's investigation efforts concerning international terrorism was posted on the Internet. Most of the documents are believed to have been prepared by the Metropolitan Police Department's Third Foreign Affairs Division in charge of investigation into such terrorism.

On Dec. 24, almost two months after the leak of the documents, the MPD held a news conference and said the documents included information that has "high probability" of having been handled by police officers. But it stopped short of clearly stating that they were genuine police records.

The documents included not only information on investigation targets but also the names of informants and investigators. The personal information in the documents concerned some 1,000 people, excluding police officers. The MPD says it still cannot contact about 30 percent of these people. The documents also mentioned people shadowed by investigators and the results of the checks of the immigration status of targeted people and of inquiries concerning their bank accounts.