The FBI has told lawmakers that it has found more emails from Hillary Clinton's private email server.

House Oversight and Government Reform Committee Chairman Jason Chaffetz, R-Utah, said in a tweet that he believes that means the case is being "reopened." That was confirmed in FBI Director James Comey's letter to lawmakers.

Comey noted that while he said the investigation was completed, "I am writing to supplement my previous testimony."

"In connection with an unrelated case, the FBI has learned of the existence of emails that appear to be pertinent to the investigation," he wrote to lawmakers.

"I am writing to inform you that the investigative team briefed me on this yesterday, and 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."

The email scandal has dogged Clinton's campaign for more than a year, and has been a continuous problem for her as she tries to woo voters. Polls have shown that Clinton has a trust problem with voters, and the email problem is a major reason why.

Clinton said for months that she never sent or received classified emails from her server, but the FBI said dozens of classified emails were sent on her system.

House Judiciary Committee Chairman Bob Goodlatte, R-Va., said the FBI's move shows that Clinton and her team "committed wrongdoing and jeopardized national security."