MONACO - The IOC will impose a "zero tolerance" punishment if accusations of widespread doping by Russian athletes are proved, IOC president Thomas Bach said Saturday. "What is important for the IOC is that we take these allegations seriously," Bach told a news conference when asked about the doping claims made in a German television documentary. He said the IOC had written to the International Association of Athletics Federations (IAAF) ethics commission demanding "to be informed about all the results which may affect people and the jurisdiction of the IOC."  "If such allegations should be proven by the IAAF ethics commission then the IOC will react with its zero tolerance policy," Bach vowed. Russian officials have strongly denied the claims of state-backed doping made in the documentary.