Rep. Tim Ryan (D., Ohio) suggested to CNN's Wolf Blitzer on Friday that the Russians may have played a role in the FBI reopening its investigation into Hillary Clinton's private email server after discovering new documents.

"So the question is: Where did these come from? How did they get to the FBI? Is Russia involved in this? We don't have a clue where this stuff is coming from," Ryan said.

FBI Director James Comey announced Friday afternoon that the federal investigation into Clinton's private email server had been reopened.

"In connection with an unrelated case, the FBI has learned of the existence of emails that appear to be pertinent to the investigation … I agreed that the FBI should take appropriate investigative steps designed to allow investigators to review these emails to determine whether they contain classified information, as well as to assess their importance to our investigation," Comey wrote in a letter to the Senate Judiciary Committee.

Ryan also said that he did not know if the hacked emails from Clinton campaign chair John Podesta's account were altered in any way. Podesta and others in Clinton's campaign have remained silent on the authenticity of the emails.

Ryan said Clinton had been thoroughly vetted on the issue of her private emails and that he has moved on from the matter.