(Bloomberg) -- Former President Donald Trump lost a critical court battle to keep legal details secret from the Justice Department about his alleged mishandling of classified information and obstruction of justice after he left the White House.

The rebuke represents a double whammy, as it also appears to clear the way for Special Counsel Jack Smith to force one of Trump’s private lawyers to testify before a grand jury, possibly as early as this week.

The US Court of Appeals for the DC Circuit on Wednesday denied requests by Trump and his lawyers to halt a judge’s order that allows Smith’s office to pierce legal privileges that cover an attorney’s conversations with their client as well as their written work. 

The latest order isn’t a final opinion on the merits of the fight, but it does indicate that a three-judge panel wasn’t persuaded at this stage that Trump is likely to win. Trump could ask all active judges on the DC Circuit to reconsider the panel’s decision or petition the US Supreme Court to get involved. 

Much of the legal fight remains sealed, but people familiar with the situation previously confirmed that the two consolidated appeals before the DC Circuit challenged a March 17 ruling by US District Judge Beryl Howell. One appeal involves Trump’s assertion of attorney-client privilege over information about his communications with Evan Corcoran and the second involves prosecutors’ access to material Corcoran prepared related to his representation of Trump.

The court’s full order wasn’t public and only explicitly referred to the production of documents. But two sources who requested anonymity to discuss nonpublic proceedings had said that Trump’s appeal on the attorney-client privilege issue was aimed at preventing Corcoran from testifying again before the grand jury. The DC Circuit’s denial of requests by Trump’s team for stays in both matters indicate that the order covered the testimony and documents fights.

Federal prosecutors convinced Howell that Trump used at least one of his lawyers in furtherance of criminal activity, according to one of the people familiar with the matter who asked to remain anonymous speaking about ongoing matters. The finding was previously reported by ABC News.

Legal protections known as attorney-client privilege and the attorney work-product doctrine normally would shield Corcoran from being forced to comply with the government’s demands for his testimony and for his records.

But prosecutors successfully argued before Howell that the “crime-fraud exception” to those privileges should apply in this case. That exception kicks in when the government can present evidence that a client may have used their lawyer to commit an ongoing or future crime. 

Trump’s lawyers immediately appealed and the DC Circuit set an unusually swift schedule. Trump’s team was ordered to file additional briefing by midnight the same day they asked the appeals judges to put Howell’s ruling on hold. The government was required to file its response to Trump’s motions by 6 a.m. the next day.

The case was before two of President Joe Biden’s nominees to the court, Judges J. Michelle Childs and Florence Pan, and Judge Nina Pillard, who was confirmed under former President Barack Obama.

A spokesperson for Smith’s office declined to comment. A Trump spokesperson did not immediately return a request for comment.

The federal grand jury in Washington is hearing evidence in a different investigation than one in New York, which has been weighing criminal charges against Trump over alleged hush money payments during the 2016 election.

Corcoran is part of a team of lawyers who have been representing Trump in connection with the classified documents probe as well as a separate investigation under Smith into efforts to overturn or interfere with the results of the 2020 presidential election. In the months leading up to last summer’s court-authorized FBI search of Trump’s Mar-a-Lago estate, Corcoran had been communicating with the Justice Department as they tried to take stock of whether Trump still had documents with classified markings in his possession.

Corcoran appeared before the federal grand jury in Washington in January, but prosecutors wanted him to return to answer additional questions that Trump contends involve privileged communications. 

(Updated with additional information about the court’s order.)

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