CNN) -- A videotape on a Russian Web site allegedly showing a State Department employee having sex with a prostitute is a "smear campaign" meant to discredit the man, a State Department spokesman said Thursday. The employee, Brendan Kyle Hatcher, denied any encounter with a prostitute to his superiors at the U.S. Embassy in Moscow, another State Department official said. State Department spokesman Ian Kelly said the U.S. ambassador to Russia, John Beyrle, "supports" Hatcher, who remains at his job at the embassy.