The Federal Bureau of Investigations will reopen the investigation into Hillary Clinton’s use of a private email server exclusively during her time as Secretary of State.

In a letter to Congress, FBI director James B. Comey revealed that the bureau had learned of more emails connected to the investigation.

“I am writing to inform you that the investigative team briefed by 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,” Comey wrote.

Previously, Comey testified that the investigation was closed, but said that “recent developments” caused him to “supplement” his testimony.

Comey did not give a timeline for the conclusion of the investigation.

House oversight committee chairman Jason Chaffetz reacted to the news on Twitter.

“Case reopened,” he commented, citing Comey’s letter.