Former CIA chief John Brennan subpoenaed in Florida "grand conspiracy" probe

Former CIA Director John Brennan was subpoenaed to testify before a grand jury in Florida as part of a "grand conspiracy" investigation into Obama- and Biden-era officials last week, on the same day the lead prosecutor on the case abruptly resigned, court records show.

The subpoena, signed by former prosecutor Joe diGenova, asked Brennan to appear before a grand jury in Fort Pierce, Florida, on Oct. 15, his attorney Kenneth L. Wainstein revealed in a sworn statement Monday.

diGenova resigned from his role overseeing the investigation on Thursday, amid growing disagreements between senior department officials in Washington over the management of the probe, sources familiar with the matter told CBS News. diGenova confirmed his resignation to CBS News last week, but did not comment on why he left the Justice Department.

Wainstein said Brennan's lawyers spoke by phone on Friday with Kurt Olsen, another prosecutor involved in the case. Olsen told Brennan's legal team he is considered a "subject" in the grand conspiracy probe, which is looking into whether Obama- and Trump-era officials conspired to deprive President Trump of his rights to keep him out of public office.

"In that call, Mr. Olsen fielded our inquiries and indicated there are multiple 'viable' grand jury investigations, including a 'far-reaching' investigation in Fort Pierce that includes "issues at Mar-a-Lago and beyond" into whether President Trump had his civil rights violated," Wainstein wrote in his sworn statement.

He also told Brennan's lawyers that the Obama-era CIA chief remains a "target" in a narrower investigation looking into whether he lied to Congress during congressional testimony about the intelligence community assessment into Russian interference in the 2016 presidential election.

Olsen told his lawyers that the narrower case into whether Brennan lied to Congress also remained "viable."

In Justice Department parlance , somebody is considered a "target" when prosecutors believe there is evidence linking them to a crime and view them as a "putative defendant." A "subject" is a person who is not necessarily a target yet, but "whose conduct is within the scope of the grand jury's investigation."

The news of the subpoena came in court filings stemming from Brennan's lawsuit against the Justice Department . Brennan alleges the investigations targeting him are politically motivated, and is seeking a court order to force the preservation of records and communications of top department and White House officials.

On Monday, Brennan's legal team asked a federal judge to grant Brennan's motion for a preliminary injunction in the case.

"The threat of prosecution remains quite real," Wainstein argued to U.S. District Judge Jia Cobb, adding that there have been "intentional efforts" by the Justice Department to hide potential misconduct in the case.