The disposal is taking place as the Cabinet Office's inspector-general for public records management does not have the authority to check official documents that are archived for less than a year.

There are no other mechanisms to monitor the handling of documents kept for such a short period. Agencies can refuse to submit such documents to the Cabinet Office and scrap them if they decide that their publication may have a significant adverse impact on national security.

Experts said that once the documents are scrapped, it would be difficult for a third party to review the adequacy of the handling of the designated state secrets. This may increase the risk of the arbitrary use of the controversial law, which came into force in 2014, and make ineffective the government's functions to check the handling of the classified documents.

The agencies that have been scrapping such documents are the Foreign Ministry, the Defense Ministry, the National Security Secretariat, and the Fire and Disaster Management Agency, according to a report made public in March by the House of Representatives Board of Oversight and Review of Specially Designated Secrets. (Jiji Press)