Keller was charged with knowingly entering or remaining in any restricted building or grounds without lawful authority, violent entry and disorderly conduct on Capitol grounds, and obstructing law enforcement engaged in official duties incident to civil disorder, according to documents filed in US District Court in Washington, DC.
It is unclear whether Keller has an attorney and whether he is in custody.
CNN has been unable to contact Keller for comment.
He is best known for anchoring the winning US team in the 4×200-meter freestyle relay at the 2004 Olympic Games in Athens, in which he held off gold medalist Ian Thorpe of Australia.
The court documents also say research showed Keller was identified by media outlets such as SwimSwam, which covers competitive swimming.
FBI Special Agent Matthew R. Barofsky wrote in court documents that he confirmed Keller’s identity by comparing photos he was in to his Colorado driver’s license.
The photos from the Capitol also show Keller is wearing a US Olympic Team jacket and “appears to be one of the tallest individuals,” Barofsky writes in his statement of facts. Keller is 6 feet, 6 inches tall.
Correction: A previous headline on this story incorrectly stated Keller’s status. He has been charged and a warrant has been issued for his arrest. CNN has not confirmed whether he has been arrested.