As part of the investigation, the bureau is examining payments of $500,000 in bitcoin, apparently by a French national, to key figures and groups in the alt-right before the riot, the sources said. Those payments were documented and posted on the web this week by a company that analyzes cryptocurrency transfers. Payments of bitcoin, a cryptocurrency, can be traced because they are documented on a public ledger.

Separately, a joint threat assessment issued this week by the FBI, the Department of Homeland Security and various other federal and D.C.-area police agencies noted that since the Jan. 6 riot, “Russian, Iranian, and Chinese influence actors have seized the opportunity to amplify narratives in furtherance of their policy interest amid the presidential transition.”

Russian state and proxy media outlets “have amplified themes related to the violent and chaotic nature of the Capitol Hill incident, impeachment of President Trump, and social media censorship,” the unclassified intelligence report said. “In at least one instance, a Russian proxy claimed that ANTIFA members disguised themselves as supporters of President Trump, and were responsible for storming the Capitol building.”