Supporters of Donald Trump who invaded the US Capitol earlier this week reportedly smeared faeces and urinated on the floors.
"Congressional staffers saw faeces in the hallways," a source close to Senate Majority Leader Chuck Schumer told the New York Post, calling it "an intentional effort to degrade the Capitol building".
"It came from the bathroom and they tracked it around."
The source told the Sun-Sentinel paper there were poop footprints in several hallways.
Hakeem Jeffries, a Democrat from New York who represents Brooklyn and Queens, said there was also "clear desecration" in the form of urine.
Another representative said the rioters, many of whom are now being hunted down by the FBI, stole a memorial to the late John Lewis, a civil rights activist and politician who died last year.
As the terrorists - as President-elect Joe Biden called them - were turfed out of the Capitol, Trump released a video calling them "very special" and that he loves them.
In a post on Twitter on Saturday (NZ time) he called his supporters "patriots".
Five people died in the violence, including one police officer.
Trump has been accused of stoking the violence.
"If Trump had said to his supporters, 'You must absolutely in no circumstances take this issue onto the streets and in any way contest the result," that would have been different," University of Otago international relations professor Robert Patman told Newshub on Friday.
"But he hasn't done that. Trump has set the tone and created an environment in which this sort of mob riot... was possible."
Moves are underway to impeach the President a second time, this time potentially with the support of Republicans - making Trump's removal a very real possibility, less than two weeks before his term ends.