West German politician Uwe Barschel, who was found dead last month in his Geneva hotel bathtub, died of a drug overdose, a police autopsy said. " . . . The death of Mr. Uwe Barschel was due to severe intoxication with medical drugs," Geneva investigating judge Claude-Nicole Nardin said in a statement. Barschel, former premier of the state of Schleswig-Holstein, resigned in September after allegations that he had directed a dirty-tricks campaign against his political opponent. Geneva police had said the death appeared to be a suicide, but Barschel's family charged that he was murdered under mysterious circumstances. The autopsy statement did not mention suicide.