The State Department said Monday it is reviewing nearly 15,000 previously undisclosed emails recovered as part of the FBI’s now-closed investigation into the handling of sensitive information that flowed through Hillary Clinton’s private home server.

Lawyers for the department told U.S. District Court Judge James E. Boasberg on Monday that they anticipate processing and releasing the first batch of these new emails in mid-October, raising the prospect new messages sent or received by Democratic nominee could become public just before November’s presidential election. The judge is overseeing production of the emails as part of a federal public-records lawsuit filed by the conservative legal advocacy group Judicial Watch.

Representing the State Department, Justice Department lawyer Lisa Olson told Boasberg that officials do not yet know what portion of the emails is work-related rather than personal. Clinton, the Democratic nominee for president, served as secretary of state from 2009 to 2013. She has claimed that she deleted only personal emails prior to returning over 55,000 pages of her work-related messages to the State Department last year.

The State Department has publicly released most of those work-related emails, although some have been withheld because they contain information considered sensitive to national security.