Sept 24 (Reuters) - Russian wrestler Bilyal Makhov, who won a gold medal in the 120kg freestyle competition at the London Olympics, has been banned for four years for an anti-doping violation, the Russian Anti-Doping Agency (RUSADA) said. The 34-year-old"s suspension was backdated to Jan. 27, 2020, it said in a statement TASS news agency reported that Makhov had tested positive for a banned substance and that a spokesperson for RUSADA said he had failed to provide documented explanations about how it had entered his body. The agency added that Makhov"s representative told them the wrestler was banned because he had failed to report a medical preparation in his Therapeutic Use Exemption (TUE) list. The Russian wrestling federation did not immediately reply to a Reuters request for comment. The three-times world champion had initially won bronze alongside Iranian Komeil Ghasemi at the 2012 Games but both wrestlers" medals were upgraded to gold after the finalists, Artur Taymazov and Davit Modzmanashvili, were disqualified in 2019 for doping violations.