The US House of Representatives committee probing the deadly January 6 riot at the Capitol said on Tuesday it has issued five subpoenas to far-right extremist groups and people associated with those groups.
The committee said it had issued subpoenas seeking evidence and documents on the Proud Boys and Henry “Enrique” Tarrio, its chairman, as well as on the Oath Keepers and its president, Elmer Stewart Rhodes.
The Democrat-led committee also issued a subpoena to Robert Patrick Lewis, chairman of 1st Amendment Praetorian, a lower-profile organisation known for wearing black shirts and providing security at events showing support for former president Donald Trump.
Thousands of Trump supporters stormed the Capitol on January 6 in a failed attempt to prevent formal congressional certification of his election loss to Joe Biden. The committee is scrutinising Mr Trump's actions related to those events.
About 700 people have been charged with taking part in the riot at the Capitol. It was the worst attack on the seat of the US government since the War of 1812.
The January 6 Select Committee has sent subpoenas to at least 45 people linked to the attack.
More than 20 suspected members of the Oath Keepers have been arrested on charges of taking part in the assault on the Capitol. At least 18 Proud Boys members have been detained on charges including conspiracy and assaulting police officers.
Tarrio is serving a five-month sentence at a jail in Washington after pleading guilty in July to two crimes, including stealing and then setting fire to a Black Lives Matter banner during a tumultuous demonstration following Mr Trump’s electoral defeat.