US Capitol Police have contradicted a report from news channel CNN that reported an agent from the US parliament building had died.
Police say several officers are injured in the hospital, but none of them has died.
According to CNN, three sources to the American news channel CNN had confirmed the death.
After the raid on the buildings of the US Congress by supporters of President Donald Trump, the death toll is still at four.
One woman was killed by a firearm on Wednesday (local time), and three others died of unknown causes.
An unknown number of people were injured. Dozens of people have been arrested, and more arrests are expected.