Attorneys for Andrew McCabe are demanding to know whether a District of Columbia grand jury has rejected an indictment of the ex-deputy FBI director. His lawyers sent a letter Friday morning to Justice Department officials after hearing "rumors from reporters" that the grand jury had declined to vote to indict him.

"We have no independent knowledge of whether the reporting is accurate but for present purposes we assume that the grand jury may have voted a no true bill," McCabe's legal team wrote, citing media reports from the Washington Post and the New York Times as indications that their client may not be facing federal criminal charges after all. A "no true bill" refers to a conclusion by a grand jury that there isn't sufficient probable cause to charge a defendant.

On Thursday a person familiar with the case told CBS News that McCabe had appealed criminal charges recommended by the U.S. attorney for the District, Jessie Liu, to Deputy Attorney General Jeffrey Rosen. The department ultimately denied the request.

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The letter was sent to Justice Department officials including Liu and Ed O'Callaghan, deputy principal of the office of the deputy attorney general.

The Justice Department and the District of Columbia U.S. attorney's office declined to comment.

If the grand jury has chosen not to indict McCabe and instead voted for the "no true bill," that would be a rare occurrence because prosecutors only need to convince 12 of the 23 grand jurors in order to secure an indictment, or a "true bill." Prosecutors have the option of presenting the case to a grand jury again, but that would require Liu's approval. McCabe's attorney, Michael Bromwich, urged the Justice Department against taking this path.

"We believe that given the length of this investigation, and the resources devoted to it, this is not a case where authorizing resubmission of the case to a grand jury is consistent with this standard," Bromwich wrote. "If the grand jury voted not to approve charges, it did not find probable cause. Therefore, it is simply not reasonable to believe that a trial jury would find Mr. McCabe guilty of any charges employing a far more rigorous and exacting standard — beyond a reasonable doubt."

McCabe was fired in March 2018 after a Justice Department inspector general report found McCabe had displayed a "lack of candor" after repeatedly misstated his involvement in a news media disclosure regarding an FBI investigation into the Clinton Foundation. McCabe is currently suing the Justice Department and the FBI over the circumstances of his firing.