The five-time Olympic medallist had previously been hit with three federal charges, but a grand jury has indicted him on seven counts.

Court documents show that Keller is charged with civil disorder, obstructing an official proceeding, entering and remaining in a restricting building or grounds, disorderly and disruptive conduct in a restricting building or grounds, disorderly conduct in a Capitol building, impending passage through the Capitol grounds or buildings, and finally parading, demonstrating, or picketing in a Capitol building.

The Hill reports that Keller was released on bond after being arrested last month.

Keller was identified in video footage taken inside the Capitol Building, in part because he was wearing a United States Olympic Team jacket.

Five people, including a police officer, died during the riot on January 6.

Former US President Donald Trump is currently the subject of an impeachment trial as a result, accused if inciting an insurrection.

Keller earned two Olympic gold medals and one silver with the American men's 4x200 metres freestyle relay team, triumphing at Athens 2004 and Beijing 2008 and finishing second at Sydney 2000. 

The 38-year-old also claimed bronze medals in the men's 400m freestyle at Sydney 2000 and Athens 2004.

Keller was known to be a Trump supporter and commercial real estate firm Hoff and Leigh issued a statement after the riot stating that Keller, an independent contractor, had resigned in the wake of the incident.

Both the US Olympic and Paralympic Committee and USA Swimming condemned the riot.

It has been suggested that, if found guilty, those charged in connection with the storming of the Capitol Building could face prison sentences of 10 years.