He called the investigation a "Witch Hunt" and said the person in charge of the investigation is the same man who told him to fire the FBI Director.
Taking to his most preferred social media platform - Twitter - Trump posted several tweets addressing the investigation.
"I am being investigated for firing the FBI Director by the man who told me to fire the FBI Director! Witch Hunt"
He did not give any name but it is likely he was referring to Deputy Attorney General Rod Rosenstein. Rosenstein penned a memo last month raising concerns about Comey’s handling of the Hillary Clinton email investigation that the White House used to justify his firing.
Amid a firestorm of criticism of Comey’s firing, Rosenstein appointed former FBI Director Robert Mueller as a special counsel to oversee the federal investigation into Russian meddling in last year's election.