The U.S. Department of Energy's Office of Inspector General says a lack of managerial oversight at Los Alamos National Laboratory led to improper disclosures of sensitive information.

In a summary of a report released last week, the inspector general says the lab's classification officer at times misclassified national security information.

The summary, which is dated Wednesday, says there were at least six incidents where lab documents were misclassified.

It also says lab officials didn't investigate any alleged violations by the classification officer.

The inspector general says it has made recommendations to boost management of information in its full report.

The investigation partly stems from last year's firing of a lab worker for an article he wrote.

James Doyle says the article was approved for publication by the lab's classification office.