Multiple U.S. news outlets say material from a binder containing "highly classified" information related to Russian efforts to influence the 2016 U.S. elections or the subsequent investigation into alleged meddling vanished in the waning days of the Trump administration, fueling concerns of a leak of closely guarded secrets including secret sources and methods. The December 15 reports by CNN, which broke the story, The New York Times, and Reuters all quote anonymous sources. They say the possible disappearance of raw intelligence including from U.S. and NATO allies in the so-called "Crossfire Hurricane" binder prompted a briefing last year of the Senate Intelligence Committee. Reuters said former President Donald Trump's presidential campaign did not immediately respond to a request for comment.