SAKHIR, Bahrain : Russian oligarch Dmitry Mazepin's appearance at Formula One's pre-season testing in Bahrain caused a stir and triggered questions on Friday about his presence in the paddock. Mazepin's son Nikita raced for the U.S.-owned Haas team before Russia invaded Ukraine in February 2022 and the deal was ended. Dmitry has been described by the European Union as "a member of the closest circle" of Russian President Vladimir Putin and remains on an EU sanctions list which his son was