Lawyers for Andrew McCabe asserted Thursday that the D.C. U.S. attorney’s office is refusing to say whether a grand jury declined to indict the former acting FBI director and complained of inappropriate media leaks they claimed could only have come from the Justice Department.

The statement is the latest move in McCabe’s aggressive effort to dissuade federal prosecutors from charging him with lying to investigators about a media disclosure. His attorneys, Michael R. Bromwich and David Schertler, asserted that prosecutors were ignoring their many inquiries and that they were “considering a range of options in response to that lack of information and the troubling events of the past week.”

“This investigation has been fatally flawed from its inception,” the lawyers said in the statement. “It has been irrevocably tainted by the President’s targeting of Mr. McCabe for prosecution. The investigation has now dragged on for more than 18 months with no resolution in sight.”

Spokespeople for the U.S. attorney’s office in the District of Columbia and the Justice Department declined to comment.

The allegation — which Mc­Cabe disputes — stems from an April 2018 inspector general report, which found that the former acting FBI director lied four times, three of them under oath, about his role in authorizing other bureau officials to talk to a reporter about an investigation of Hillary Clinton’s family foundation.

The inspector general’s office referred its findings to federal prosecutors in the District, and they soon began using a grand jury to conduct their inquiry. But months, then a year, passed with no action.

McCabe’s legal team met last month with U.S. Attorney Jessie K. Liu and Deputy Attorney General Jeffrey Rosen to press its case. Among his attorneys’ concerns is whether McCabe, who authorized the FBI to begin investigating President Trump, is being targeted more aggressively because the president considers him a political foe.

Last week, it seemed charges were imminent. The grand jury, which had not been seen for months, was called back in. The Justice Department informed McCabe, 51, that Rosen had rejected his appeal. But grand jurors left with no sign that an indictment had been returned. McCabe’s team asked prosecutors whether that was because the panel had refused to approve charges — which would be a significant embarrassment to the Justice Department and the U.S. attorney’s office.

McCabe’s team said in its statement that it was told by reporters on Sept. 11 that “the grand jury was being convened and that we should expect an indictment of Mr. McCabe that afternoon.” But his lawyers said reporters later told them that the grand jury would return the following day and that McCabe would then be indicted.

“The reporters could only have obtained this information from personnel at the Department of Justice (DOJ) or the U.S. Attorney’s Office and such leaks are prohibited by rules governing grand jury secrecy,” McCabe’s team alleged.

On Sept. 12, the deputy attorney general’s office told McCabe his appeal to avoid charges had been denied. But the grand jury returned no public indictment. McCabe’s team wrote that it then began inquiring about what had happened and asking the Justice Department to investigate leaks.

“The U.S. Attorney’s Office has not responded to any of the letters described above, nor have the letters even been acknowledged,” McCabe’s team wrote.

To bring charges against McCabe, prosecutors would have to convince 12 of 23 grand jurors that there was probable cause that he had committed a crime. It is joked about in legal circles that prosecutors can “indict a ham sandwich” because that standard is so low.

But it is not unheard of for grand juries to decline to indict. In a famous case from the 1980s, a grand jury declined to indict former professional tennis player Vitas Gerulaitis in a drug case after his attorney waged a public campaign to present his side of the issue and said he expected charges before they were filed.

Prosecutors can present their case to a different grand jury if they are turned down — though they would do so knowing they might face challenges at a later trial, where they could have to convince 12 jurors unanimously that they had proved their case beyond a reasonable doubt.

McCabe’s team called on prosecutors to abandon the effort.

“It is deeply unfair to Mr. McCabe and his family,” the lawyers wrote. “It is a waste of governmental resources. The U.S. Attorney’s Office should close this investigation immediately and move on to fight battles more worthy of the traditions of the Department of Justice.”

Spencer S. Hsu contributed to this report.