Congressman Kevin McCarthy, the top Republican in the US House of Representatives, and four other lawmakers have received subpoenas from the House committee investigating the January 6, 2021, insurrection at the Capitol by Donald Trump’s supporters.

The committee issued the subpoenas to try to secure the lawmakers’ testimony after they had rejected voluntary co-operation with the investigation.

The other Republican lawmakers receiving subpoenas were Representatives Jim Jordan, Mo Brooks, Scott Perry and Andy Biggs.

All five lawmakers on Thursday said they believed the committee’s investigation was partisan and illegitimate but did not directly answer questions about whether they would comply with the subpoenas.

“This whole thing is a charade,” Mr Perry said.

In January, Mr McCarthy said in a statement that he would not cooperate with the Jan. 6 House select committee’s probe.

“As a representative and the leader of the minority party, it is with neither regret nor satisfaction that I have concluded to not participate with this select committee’s abuse of power that stains this institution today and will harm it going forward,” Mr McCarthy’s statement said.

On January 6, 2021, supporters of Republican Trump stormed the Capitol building, encouraged by the then-president in a speech outside the White House to protest formal congressional certification of Democrat Joe Biden’s victory over him in the November 2020 election.

The committee is trying to establish what Mr Trump did while thousands of his supporters attacked police, vandalised the Capitol and sent members of Congress and then-vice president Mike Pence running for their lives.

Representative Bennie Thompson, a Democrat and select committee chairman, said in a statement that the five House Republicans who received subpoenas had information about events leading up to the attack.

“Before we hold our hearings next month, we wished to provide members the opportunity to discuss these matters with the committee voluntarily,” Mr Thompson said.

“Regrettably, the individuals receiving subpoenas today have refused and we’re forced to take this step to help ensure the committee uncovers facts concerning January 6th.”

Mr McCarthy, who has faced criticism from fellow conservatives within his caucus, publicly zigzagged on Mr Trump’s culpability by first saying the former president bore some responsibility for the violence, but finally visited Mr Trump at his Mar-a-Lago resort home in Florida and posed for a photograph with him.

– AAP