Former President Donald Trump on Monday sued the US congressional committee investigating the 6 January riot at the Capitol, claiming members made an illegal request for his White House records.
Trump, in a lawsuit filed in US District Court for the District of Columbia, asserted that materials sought by the House of Representatives committee are covered by a legal doctrine known as executive privilege, which protects the confidentiality of some White House communications.
"The Committee's requests are unprecedented in their breadth and scope and are untethered from any legitimate legislative purpose," Trump's lawyer Jesse Binnall wrote in the lawsuit.
Committee members Liz Cheney, a Republican from Wyoming, and Bennie Thompson, a Democrat from Mississippi, said in a written statement issued in response to Trump's lawsuit that the former president was seeking to "delay and obstruct" their investigation.
"It's hard to imagine a more compelling public interest than trying to get answers about an attack on our democracy and an attempt to overturn the results of an election," Cheney and Thompson said in the statement.
Hundreds of Trump supporters stormed the seat of Congress on 6 January in a failed bid to prevent lawmakers from certifying Democratic President Joe Biden's election victory. More than 600 people face criminal charges stemming from the event.
Trump was impeached by the Democratic-led House on a charge of inciting the attack on the Capitol in a fiery speech at a rally earlier that day. He was acquitted by the Senate.
Biden earlier this month authorised the National Archives to turn over an initial batch of documents requested by the select committee. The Archives has said it would turn over the requested material next month, according to Trump's lawsuit, which seeks an injunction halting that process.
Michael Stern, a former congressional lawyer, said Trump's strategy may be to use litigation to stall the select committee's work.
"If he is willing to pay for the lawyers, Trump could delay the production of records for some time," Stern said.
The Jan. 6 committee has also issued subpoenas demanding testimony from Trump advisers, including political strategist Steve Bannon.
Bannon has refused to provide testimony until Trump's assertion of executive privilege has been resolved by a court or through negotiations with the committee.
The committee said last week it would formally ask the U.S. Justice Department to bring criminal charges against Bannon because of his defiance of the subpoena.
The committee has subpoenaed other officials including former Justice Department official Jeffrey Clark, Trump former chief of staff Mark Meadows, deputy chief of staff Dan Scavino and former Defense Department official Kash Patel.