Michael Flynn, the National Security Adviser to President Trump, has been under investigation—and possibly still is—for what has been described as his “repeated contacts” with a Russian official, The Wall Street Journal reported Sunday. Flynn’s communications have been under scrutiny by the FBI, CIA, National Security Agency, and the Treasury Department as part of a counterintelligence probe into ties between the Kremlin and Trump’s team, according to the report. The investigation stems from reports that surfaced this month about the retired general making phone calls to Russian Ambassador Sergei Kislyak on the very same day the Obama administration announced new sanctions against Russia. While a spokesman for Trump dismissed the phone call as nothing more than a diplomatic formality, sources cited by the Journal say the investigation concerns “repeated contacts” between Flynn and Kislyak, and prior conversations with Russian figures. No further details have been released, and it’s unclear if the investigation is still ongoing. White House spokeswoman Sarah Sanders said Sunday that the Trump administration has “absolutely no knowledge of any investigation or even a basis for such an investigation.” Flynn is not the only member of Trump’s team to face scrutiny for rubbing elbows with Russian officials. Trump seems to have surrounded himself by cheerleaders for Moscow and figures with past business dealings there, including former campaign chairman Paul Manafort and advisers Roger Stone and Carter Page.