A federal judge ruled Monday that former US president Donald Trump "more likely than not" engaged in criminal conduct with his efforts to overturn the results of the 2020 presidential election.

Judge David Carter leveled the explosive accusation in a ruling dealing with subpoenas issued by the congressional committee investigating the January 6, 2021 attack on the Capitol by Trump supporters.

The ruling comes amid US media reports that Trump's son-in-law and senior advisor Jared Kushner is expected to appear voluntarily for a virtual deposition before the committee this week.

"Based on the evidence, the court finds it more likely than not that President Trump corruptly attempted to obstruct the Joint Session of Congress," Carter said in a blistering 44-page ruling.

The committee had sought documents from John Eastman, a conservative lawyer who provided legal advice to Trump in the wake of his November 2020 election loss to Democrat Joe Biden.

Trump supporters storming the US Capitol on January 6, 2021
Trump supporters storming the US Capitol on January 6, 2021 AFP / Olivier DOULIERY

Carter, a Clinton appointee who serves on a US District Court in California, rejected Eastman's attempt to block handing over emails to the committee from his account at Chapman University, the California school where he was a law professor.

Eastman notably authored memos providing dubious legal arguments for how then-vice president Mike Pence could swing the election to Trump when Congress met on January 6 to certify the results of the vote.

In his ruling, Carter noted that Trump had repeatedly urged Pence to throw out Electoral College votes from contested states and had done so in a fiery speech to his supporters shortly before the storming of Congress.

The judge's ruling may increase pressure on US Attorney General Merrick Garland to bring charges against former president Donald Trump
The judge's ruling may increase pressure on US Attorney General Merrick Garland to bring charges against former president Donald Trump AFP / Jim WATSON

Pence resisted the pressure, and Biden was certified the winner by Congress after the Capitol was cleared of rampaging Trump supporters.

"Because President Trump likely knew that the plan to disrupt the electoral count was wrongful, his mindset exceeds the threshold for acting 'corruptly,'" the judge said.

He added that Trump likely knew his allegations of election fraud were baseless, and therefore that the plot was unlawful.

The judge's ruling may increase pressure on Attorney General Merrick Garland to bring charges against the 75-year-old Trump over the Capitol riot, which left at least five people dead and 140 police officers injured.

Garland has declined to reveal whether Trump is the target of any Justice Department investigation but has said the probe will continue "until we hold everyone accountable who committed criminal acts with respect to January 6."

A US district judge said former president Donald Trump's efforts to overturn the 2020 election amounted to criminal conduct
A US district judge said former president Donald Trump's efforts to overturn the 2020 election amounted to criminal conduct AFP / SAUL LOEB

More than 775 people have been arrested in connection with the Capitol attack. Some 280 have been charged with obstructing an official proceeding.

Trump was impeached for a historic second time by the House after the riot -- he was charged with inciting an insurrection -- but was acquitted by the Senate.

"Dr. Eastman and President Trump launched a campaign to overturn a democratic election, an action unprecedented in American history," Carter said in his ruling.

"Their campaign was not confined to the ivory tower -- it was a coup in search of a legal theory."

The judge ordered Eastman to disclose 101 documents to the House select committee investigating the January 6 attack while keeping 10 documents privileged.

The bipartisan panel, which is nearing the end of its investigation ahead of public hearings expected in May, launched criminal proceedings on Monday evening against Trump's trade director Peter Navarro and deputy chief of staff Dan Scavino.

It voted unanimously to ask the full Democratic-controlled House to cite the pair for criminal contempt of Congress after they refused to testify to the probe, in defiance of subpoenas.

Scavino was the ex-president's social media manager, and they were together at the White House as the mob began its attack, according to investigators.

Navarro has bragged on cable news about his role in organizing the plot to overturn the election with the help of around 100 Republican lawmakers.

"This is America. There is no executive privilege for presidents or trade advisors to launch coups or insurrections," said Jamie Raskin, a Democratic committee member.

The panel has previously recommended prosecution for senior Trump aides Mark Meadows and Steve Bannon, as well as ex-Justice Department official Jeffrey Clark.

Only Bannon is being prosecuted so far, however, and the Clark citation didn't even make it to the floor of the House.

The panel was due to continue behind closed doors after the vote to consider seeking agreement to call Ginni Thomas, the right-wing activist wife of Supreme Court Justice Clarence Thomas, to testify.

Her text messages in late 2020 and early 2021, turned over to the committee by Meadows, show she pushed repeatedly for Trump aides to work to overturn the election.