WASHINGTON — The State Department has completed its internal investigation into former Secretary of State Hillary Rodham Clinton's use of private email and found violations by 38 people, some of whom may face disciplinary action.

The department determined that those 38 people were "culpable" in 91 cases of sending classified information in messages that ended up in Clinton's personal email. The 38 are current and former State Department officials but were not identified in the report that was sent to Congress this week.

The investigation covered 33,000 emails that Clinton turned over for review after her use of the private email account became public. The department said it found a total of 588 violations involving information then or now deemed to be classified, but could not assign fault in 497 cases.