Capitol Police informed of the possibility of violence before riot

"Prior to this event, the FBI obtained credible and actionable information about individuals who were planning on traveling to the protests who expressed a desire to engage in violence," said the official. "The FBI was able to discourage those individuals from traveling to D.C."

NYPD also sent out information to police departments across the country, including Capitol Police, describing threats made online leading up to Jan 6.

The report contradicts previous claims by FBI officials earlier this week that they had no expectations of a violent riot occurring at the Capitol.

"Social media is just part of a full intelligence picture, and while there was First Amendment-protected activity on social media to include some people making threats, to this point, investigators have not found that there was an organized plot to access the Capitol," said the FBI official at the time.

The report also contradicts Washington DC Police Chief Robert Contee, who said previously that "there was no intelligence that suggested there would be a breach of the U.S. Capitol."

Independent investigations have discovered that multiple message boards occupied by extremists spoke about planning a breach of the Capitol, discussions which were apparently missed by major intelligence agencies and police.

"You can go to Washington on Jan 6 and help storm the Capitol," wrote one user of the website 8kun. "As many Patriots as can be. We will storm the government buildings, kill cops, kill security guards, kill federal employees and agents, and demand a recount."

The report raises further questions as to why the Capitol Police were unprepared to confront rioters on Jan 6.