Updated at 4:47 p.m. ET

An attorney for former national security adviser Michael Flynn said she briefed President Trump and a lawyer working for him on the status of Flynn's criminal case in the past two weeks, according to statements in court on Tuesday.

The lawyer, Sidney Powell, initially told the judge she was wary of disclosing the contact because of so-called executive privilege, even though she does not work for Trump or the White House.

The disclosure emerged at an unusual hearing in which the judge presiding over Flynn's case probed the Justice Department's motives for abandoning charges against the former national security adviser, who had pleaded guilty to lying to the FBI about his conversations with the Russian ambassador.

A former federal judge working as a friend of the court said the Justice Department's decision smacked of political favoritism to help a friend of the president's.

"Not for nothing, but this crime was committed in the West Wing," said John Gleeson, the former judge.

Gleeson said that this White House, more than any other since Richard Nixon, had trampled on the independence of the Justice Department and the FBI, which had yielded to pressure from the president to drop the case against Flynn.

Trump has tweeted or retweeted more than 100 times about what he views as the unfairness of the Flynn case, but Gleeson and the government lawyers disagreed about whether the presiding judge, Emmet Sullivan, should weigh those comments in deciding how to proceed.

Flynn's lawyers allege bias

Powell, the lawyer for Flynn, argued the case had been infected by bias from FBI investigators and a failure to turn over evidence that would have helped his defense. She also trained her ire at Sullivan — before acknowledging that despite her criticism, she had not yet acted on it by filing a formal motion seeking to remove the judge from the case.

"It is a hideous abuse of power that continues to this very minute," Powell said of the case against Flynn.

Powell ultimately backed down from her assertion about executive privilege after the judge repeatedly pressed her about meetings and conversations she had with Trump, Attorney General William Barr and Deputy Attorney General Jeffrey Rosen.

Legal experts pointed out that the privilege would not apply to communications between the president and a private citizen not acting as his legal counsel.

Questions about evidence tampering

Also in court on Tuesday, Sullivan said he was "floored" by a letter submitted by an attorney for former FBI agent Peter Strzok contending that someone had doctored his notes in the case from early January 2017 — potentially to cast aspersions on former Vice President Joe Biden.

The judge said someone from the government would have to make a certification to him in the coming days about the integrity of the evidence.

Trump, Flynn's camp and supporters have sought to use Strzok's notes to tie Biden to what they call the biased treatment Flynn received from authorities — although former Deputy Attorney General Sally Yates sought to deflate that narrative at a Senate hearing last month.

Sullivan also asked whether it would be "appropriate" for him to dismiss the current lying-to-the-FBI case against Flynn — but leave it for a future Justice Department and a future attorney general to consider prosecuting him on other false statements and Foreign Agent Registration Act charges for his work on behalf of government interests in Turkey.

Flynn did not face prosecution over other alleged wrongdoing in which he may have been involved as part of the plea agreement in which he agreed to provide evidence in the Russia investigation — which prosecutors said he did eagerly until his relationship with the government turned sour.

Government frustration

For its part, the Justice Department said Tuesday it had not found a single appeals court case in history in which the government had sought to drop a case against a defendant and a federal judge had then denied the motion. The executive branch has the "exclusive authority" to prosecute a case, Deputy Assistant Attorney General Hashim Mooppan said.

Assistant U.S. Attorney Ken Kohl, who said he was the senior-most career lawyer in the U.S. Attorney's Office for the District of Columbia, told the judge the Flynn case now would be impossible to prosecute because of doubts that had been cast about witnesses, including Strzok, whose text messages raised questions about bias against Trump.

"The U.S. attorney's office's decision to dismiss this case was the right call for the right reasons," Kohl said.

At one point, the judge asked why no members of the team led by former special counsel Robert Mueller had signed onto the idea of walking away from the Flynn case. Separately, Mueller issued a rare public statement Tuesday after his former team member, Andrew Weissmann, published a book criticizing the investigators for pulling their punches under intense pressure from the Trump White House.

"It is not surprising that members of the special counsel's office did not always agree, but it is disappointing to hear criticism of our team based on incomplete information," Mueller wrote.

He added that the office mission was to follow the facts and act with integrity.

"That is what we did, knowing that our work would be scrutinized from all sides," he said. "When important decisions had to be made, I made them. I did so as I have always done, without any interest in currying favor or fear of the consequences. I stand by those decisions and by the conclusions of our investigation."

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