A top FBI official confirmed that the investigation into Hillary Clinton’s private email server is “ongoing,” according to a letter filed in federal court Monday.

In the Feb. 2 letter, FBI General Counsel James Baker wrote to the State Department’s acting legal advisor, Mary McLeod, saying that revealing details about the ongoing investigation could end up subverting it, Fox News reported.

AP/Andrew Harnik

AP/Andrew Harnik

“We remain unable to provide the requested information without adversely affecting ongoing law enforcement efforts,” he wrote.

The Justice Department filed the letter in connection with a Freedom of Information Act lawsuit by the legal watchdog group Judicial Watch.

In his letter, Baker wrote that in September he declined to confirm or deny the existence of any investigation into Clinton’s private email server, but now the FBI has “acknowledged generally” that a probe has been going on. “The FBI has not, however, publicly acknowledged the specific focus, scope or potential targets of any such proceedings,” he wrote.

Judicial Watch released nearly 70 pages of State Department records Tuesday that reveal former Secretary of State Hillary Clinton and her top aides, Deputy Chiefs of Staff Huma Abedin and Jake Sullivan, received and sent classified information on their non-government email accounts.

Judicial Watch President Tom Fitton said in a statement Tuesday that the emails show that Clinton “isn’t the only Obama official who should be worried about being prosecuted for mishandling classified information.” He asserted that Abedin and Sullivan should likewise be subject to scrutiny.

“The Obama State Department has now confirmed that Clinton, Abedin, and Sullivan used unsecured, non-government email accounts to communicate information that should now be withheld from the American people ‘in the interest of national defense or foreign policy, and properly classified,’” Fitton said. “When can we expect the indictments?”

Republican National Committee Chairman Reince Priebus said in a statement that the FBI’s formal confirmation of an investigation into Clinton’s private server was “another reminder” she can’t be trusted with the presidency.

“The FBI’s announcement confirms the investigation into Hillary Clinton’s secret email server is far from the routine ‘security review’ she has claimed,” he said. “Clinton’s conduct was a severe error in judgment that grossly endangered our national security and put highly classified information at risk.”