The House Judiciary Committee sued FBI agent Elvis Chan on Tuesday for flouting a subpoena to answer questions about the federal government’s alleged collusion with social media companies to censor online speech.

“Chan has violated and continues to violate his legal obligations by refusing to appear before the Judiciary Committee as required by the Subpoena, and by refusing to answer questions when there has been no assertion of privilege by the Executive Branch,” attorneys for the House’s Office of General Counsel wrote in a 46-page complaint filed in Washington, DC, federal district court.