The U.S. House select committee investigating the Capitol riot of January 6, 2021, made criminal referrals against former U.S. President Donald Trump to the Department of Justice (DOJ) on Monday afternoon.

The committee, composed of seven Democrats and two Republicans, accused Trump of inciting an insurrection, conspiracy to defraud the United States, conspiracy to make a false statement, and obstruction of an official proceeding.

The committee's request marks the first time in history that Congress has referred a former president for criminal prosecution. And Trump has already launched a campaign to seek the Republican nomination to run for the White House again in 2024.

The criminal referrals are not legally binding, and it is up to the DOJ to decide whether to pursue charges, according to U.S. legal analysts. The DOJ is running its own probe into the Capitol riot, in which Trump supporters disrupted a joint session of Congress to certify the 2020 presidential election results.

A DOJ spokesperson declined to comment, and a Trump spokesperson did not respond to a request for comment.

Monday's meeting was the last public gathering of the nine-member panel that spent 18 months probing the unprecedented attempt to prevent the government power transfer by thousands of backers of Trump, who promoted unsubstantiated claims that his 2020 election loss to Biden was the result of widespread fraud.

The committee also referred four Republican House members for failing to comply with subpoenas as it investigated the attack. The four subpoenaed representatives were Kevin McCarthy, Scott Perry, Jim Jordan and Andy Biggs. Spokespeople for Jordan, Perry and Biggs dismissed the action as political stunts and McCarthy's office did not respond to a request for comment. 

A summary of the committee's report also said the panel believed there were grounds to recommend criminal charges against some others close to Trump, including attorney John Eastman whose lawyer has responded with a statement criticizing the committee as partisan.

It named other Trump associates, including former DOJ official Jeffrey Clark, former White House Chief of Staff and House member Mark Meadows and two lawyers: Kenneth Chesebro and Rudy Giuliani, as participating in conspiracies the panel is linking to Trump. Representatives of the others did not immediately respond to requests for comment or declined to comment.

Trump has faced a series of legal problems since leaving office on January 20, 2021. His real estate company was convicted on December 6 of carrying out a 15-year-long criminal scheme to defraud tax authorities.

Trump has dismissed the many investigations as politically motivated. On Monday, he said any prosecution would mean he was improperly being charged twice, after he was impeached last year for a second time but then acquitted in the Senate.

The House Ways and Means Committee is due to meet on Tuesday to decide what to do with Trump's tax returns, which it obtained late last month after a long court fight. Trump was the first presidential candidate in decades to not release his tax returns during either of his campaigns for president.

(With input from Reuters and Xinhua)