The government improperly sealed hundreds of previously public CIA, Pentagon and other records by reclassifying them as secret on questionable grounds, an internal review said Wednesday.

The National Archives' audit of thousands of records withdrawn from public view since 1995 contends that one of every three was resealed without justification.

The investigation covered historical records held by the National Archives. But it comes amid broader debate on classifying records on national security grounds, which critics say is often done based on political expediency.