During a hearing before a federal appeals panel in Richmond, Va., federal prosecutors said that they did not give the grand jury information on Jefferson's work on legislation, covered by the "speech or debate" clause of the Constitution, The Washington Post reported. Prosecutors argued that the charges involve alleged bribes received for "constituent services."

"We certainly respect a member of Congress's right to not have legislative material used against him," Assistant U.S. Attorney Mark D. Lytle said.

Jefferson, a Louisiana Democrat, is charged with taking bribes from communications companies seeking to do business in Africa.

Jefferson's lawyers appealed a ruling by a judge in Alexandria, who agreed with prosecutors that the indictment did not involve protected areas of the congressman's work.

"Put simply, the speech or debate clause is not a license to commit crime," U.S. District Judge T.S. Ellis III wrote.