House January 6 select committee vice-chair Liz Cheney on Sunday said the panel the US Capitol riot may yet make formal criminal referrals of former president Donald Trump and his associates to the Department of Justice.

A criminal referral is essentially a letter from another part of the US government to the Justice Department, informing prosecutors that there is cause to believe a crime has been committed, warranting further action by the department.

The Justice Department is currently investigating a number of figures associated with the Capitol attack, and Attorney General Merrick Garland has said the department will not shy away of pursuing anyone who served at the highest levels of government should evidence warrant it. But the House investigation appears to have produced more evidence of wrongdoing by Mr Trump.

Asked about the possibility of the select committee making such a referral during ABC’s This Week programme, Ms Cheney replied: "We'll make a decision as a committee about it”.

"The Justice Department doesn't have to wait for the committee to make a criminal referral, and there could be more than one criminal referral,” she said.