Report on Hillary Clinton emails finds 38 State Department employees 'culpable' for sending information to her secret server in addition to hundreds of other violations as results of three-year investigation are revealed

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

The investigation, launched more than three years ago, determined that those 38 people were 'culpable' in 91 cases of sending classified information that ended up in Clinton's personal email, according to a letter sent to Republican Sen. Chuck Grassley this week and released on Friday.

The 38 are current and former State Department officials but were not identified.

The investigation covered 33,000 emails that Clinton turned over for review after her use of the private email account became public.