The FBI has found new emails from Hillary Clinton's private email server on a laptop shared by longtime aide Huma Abedin and her estranged husband, Anthony Weiner, a U.S. official said Thursday.

The emails are not duplicates of those the agency found on the private server the Democratic nominee used during her four years as secretary of state, the official told CBS News.

But the FBI does not know whether the emails are significant to their investigation, nor how many relevant documents exist, the official said.

FBI Director James Comey told Congress on Friday the agency was examining new emails found regarding their inquiry.

The documents came from Weiner, a former New York congressman who was being probed for another "sexting" scandal — revealed in late August after The New York Post photos of his online exchanges with several women, including a 15-year-old girl.

Abedin has said she had no knowledge of any of her emails being on Weiner's computer.

The FBI obtained a warrant to search the laptop Monday.

In July, Comey concluded Clinton had been "extremely careless" with her private server use despite finding several emails being marked as classified.

Attorney General Loretta Lynch two days later accepted the agency's findings and closed the nearly two-year probe without bringing criminal charges against Clinton or any of her aides.