A Justice Department spokesperson told NBC News that the department does “not comment on ongoing investigations.” NBC News, citing a source briefed on the matter, reports that CIA Director John Ratcliffe had made a criminal referral of Brennan to the Justice Department and that it's unclear what prompted the Comey investigation.

Former CIA Director John Brennan told MSNBC that he had not been alerted that he was being investigated by the FBI before the news dropped on Tuesday.