SEOUL, Nov. 21 (Yonhap) -- The Air Force last year negligently disposed of classified documents but only reported the files as missing nine months after the fact, a lawmaker said Monday.

According to Democratic Party Rep. Shin Hak-yong, an orderly of a senior Air Force officer threw away the Air Force's "Operational Plan 3600-06" and "Operational Order 2500" in December 2010.

The officer had borrowed the documents days earlier from Air Force Operations Command.

Shin, who serves on the National Assembly's national defense committee, said Operational Plan 3600-06 details the Air Force's contingency plans against North Korea, while Operational Order 2500 serves as a guideline for peacetime aerial operations.

The orderly disposed of the files before the Air Force's regular security check, during which inspectors check a given unit's handling of confidential documents. Shin said a colonel-level officer merely watched as the orderly threw away the documents, which were labeled "Military Secrets." A closed-circuit television also captured the moment when the files were tossed into a garbage truck, the lawmaker added.

Under the military law on confidentiality, all branches of the service must immediately report any missing document to the Defense Security Command, the top counterintelligence unit. Shin said the Air Force only notified the command of the incident in September of this year.