A source has confirmed to CBS News that Hillary Clinton will be interviewed by the FBI within the coming weeks, in connection with the investigation into her private email server.

One of her top aides, Huma Abedin was interviewed by the FBI at its Washington field office in April, an official familiar with the investigation told CBS News Friday.

The FBI and Justice Department have been investigating whether sensitive information that flowed through Clinton's email server was mishandled. Abedin was interviewed at the FBI's Washington field office last month. The FBI's investigation into Clinton's email server was first reported in August.

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The Clinton campaign has said it's confident that the FBI's review "will conclude that nothing inappropriate took place." There's no timetable for completing the investigation, and there have been no statements about how much longer the investigation will take.

On Wednesday, in an unrelated civil case, a federal judge in Washington said he may order Clinton to testify under oath about whether she used a private email server to evade public records disclosures.

The order from U.S. District Judge Emmet Sullivan granted a request from the conservative legal advocacy group Judicial Watch to question six current and former State Department staffers, including Abedin, about the creation and purpose of the email system.

Clinton has acknowledged during the campaign that her home-based email setup was a mistake, but insists she never sent or received any documents that were marked classified at the time.

Her private email server was found to contain information classified at a higher level than "top secret," though her campaign has always maintained that none of the documents were classified at the time they were sent or received.

Clinton has dismissed the idea that she could face legal trouble over the use of the server, responding to a debate question in March about the prospect of a federal indictment by saying, "It's not going to happen."