An heiress to supermarket chain Publix reportedly donated about $US300,000 ($A390,000) to fund a rally that preceded the deadly storming of the US Capitol by supporters of Donald Trump.

The Wall Street Journal said on Saturday the funding from Julie Jenkins Fancelli, a prominent donor to Trump’s 2020 campaign, was facilitated by far-right show host Alex Jones.

Julie Jenkins Fancelli put up at least $300,000 to assemble Trump’s supporters prior to the lethal assault on Congress. Photo: Wikipedia

It said her money paid for the lion’s share of the roughly $US500,000 rally at the Ellipse park where Trump spoke and urged supporters to “to fight”.

More than 135 people have been arrested in connection with the January 6 attack on the Capitol as Congress met to certify Democrat Joe Biden’s victory in the November election.

Five people including a Capitol Police officer died.

According to the Journal, Jones personally pledged more than $US50,000 in seed money for the rally in exchange for a speaking slot of his choice.

Jones, who has publicised discredited conspiracy theories, has hosted leaders of the Proud Boys and the Oath Keepers, two extremist groups prominent at the riot, on his popular radio and internet video shows, it said.

Jones did not immediately respond to a request for comment. Fancelli could not immediately be reached.

Meanwhile, Publix Super Markets said in a Twitter post the violence at the Capitol on January 6 was a national tragedy.

“The deplorable actions that occurred that day do not represent the values, work or opinions of Publix Super Markets.

“Mrs Fancelli is not an employee of Publix Super Markets and is neither involved in our business operations, nor does she represent the company in any way. We cannot comment on Mrs. Fancelli’s actions.”

-AAP