The Foreign Ministry has refrained from disclosing 58 percent of the research projects it commissioned from affiliated organizations or outside experts since 2002 due to confidentiality reasons, an internal ministry document showed Saturday.

According to a document obtained by Kyodo News, the results of 46 of the 79 cases commissioned during this period were kept secret from the National Diet Library.

In terms of cost, the 46 cases amounted to about 380 million yen, or 75 percent of the approximately 510 million yen paid for commissioning the 79 cases.

Ministry officials say these research projects were not meant for disclosure in the first place because they involved discretionary diplomacy.

But the revelation of a situation where large sums of public money were used for confidential research without parliamentary oversight could draw criticism about lack of transparency.

Among research treated as secret, the most expensive was a study on an arms reduction policy implementation system commissioned from the Japan Institute of International Affairs, which falls under the jurisdiction of the ministry, in April 2003 for 185.76 million yen.

The study, which involved summarizing the situation in Japan of the preparedness of the operational system concerning the Comprehensive Test Ban Treaty, stands out as a majority of the commissioned research projects cost only several million yen each.

Most of the nuclear-related projects, including a survey on uranium enrichment technology commissioned from the Japan Nuclear Cycle Development Institute for 1.36 million yen in February 2005, have not had their contents disclosed, the document showed.

A project commissioned from Radiopress, also under the ministry's jurisdiction, in April 2002 for 12.77 million yen, asking it to compile daily one- to two-page reports on print and broadcast news from Russia's Sakhalin territory, was not disclosed for the reason that the information was not of value to be presented to the National Diet Library.