Former US President Donald Trump has blasted the congressional inquiry into the Capitol riot as a "Kangaroo Court".
In a 12-page statement, he said the investigation was designed to distract Americans from the "disaster" of Democratic-led governance.
It came after the committee held two public hearings accusing Mr Trump of an attempted coup to remain in power.
The panel on Monday detailed evidence of divisions among Trump aides over whether to accept his election loss.
Supporters of Mr Trump stormed Congress on 6 January 2021 in a bid to thwart certification of Joe Biden's election victory. A separate ongoing criminal investigation has led to more than 800 arrests in nearly every state.
"Seventeen months after the events of January 6th, Democrats are unable to offer solutions," Mr Trump, a Republican, said in a statement released through his Save America PAC.
"They are desperate to change the narrative of a failing nation, without even making mention of the havoc and death caused by the Radical Left just months earlier," he continued, alluding to the rioting that erupted during US racial justice protests over the summer of 2020.
"Make no mistake, they control the government. They own this disaster. They are hoping that these hearings will somehow alter their failing prospects."
Mr Trump accused the "unselect pseudo-committee" of treason, referring to the Democratic-led House of Representatives select committee that has been conducting the inquiry for the past year.
For much of the statement, Mr Trump relitigated his unsubstantiated allegations of voter fraud. A handful of such cases, representing a tiny number of ballots overall, have been prosecuted since the November 2020 election, but nothing on any scale that could have tipped the election either way.
Mr Trump labelled the current president as "Basement Biden". "Our country is in a nosedive," he concluded, dismissing the congressional inquiry as a pretext to prevent him running again for the presidency in 2024.
Earlier on Monday, the House committee was shown video testimony on its second day of public hearings from former campaign manager Bill Stepien, who said the aides had split into two teams after the election.
He described a "team normal" of those who accepted the results of the election, and "Rudy's team", who followed the claims of election fraud peddled by Trump lawyer Rudy Giuliani.
Both Mr Stepien and another witness, former Trump adviser Jason Miller, testified that Mr Giuliani appeared to be inebriated on the night of the election.
Mr Miller said that even with results still coming in, Mr Giuliani suggested that Trump "go and declare victory and say that we'd won it outright".
Through a spokesman on Monday, Mr Giuliani denied that he was intoxicated on election night, adding that he did not know why Mr Miller would "make such a false claim".
In videotaped testimony also aired at Monday's hearing, former Attorney General Bill Barr said he had repeatedly told Mr Trump there was no basis to claims of rigged voting machines or ballot "dumps" - which he referred to as "crazy stuff".
Mr Trump, however, refused to acknowledge these concerns and continued to spread fraud claims, Mr Barr said. He testified that he was "demoralised" by his boss' claims.
"I thought, 'Boy if he really believes this stuff, he has lost contact with - he's become detached from reality, if he really believes this stuff,'" he said.
The 6 January select committee is seeking to show that the ex-president's election fraud claims led directly to an attack on the US Capitol.
But the panel will not refer Mr Trump or anyone else to the justice department for criminal prosecution, committee chairman Bennie Thompson, a Mississippi Democrat, told reporters on Monday.
"If the Department of Justice looks at it, and assumes that there's something that needs further review, I'm sure they'll do it," he said, according to CNN when asked about the chance of prison time for Mr Trump or his inner circle.
Republican vice-chairwoman of the committee, congresswoman Liz Cheney, seemed to contradict Mr Thompson moments later by tweeting that the committee "has not issued a conclusion regarding potential criminal referrals".
"We will announce a decision on that at an appropriate time."
The committee is scheduled to hold more hearings on Wednesday and Thursday later this week.