The International Olympic Committee (IOC) said Wednesday it would take up to a week to decide whether to ban Russia from the Rio Olympics over its "state" doping machine. Amid widespread agonizing within the IOC over how to handle its biggest doping scandal, the final verdict could come less than 10 days from the Rio opening ceremony on August 5. The IOC executive decided Tuesday to wait until after a Court of Arbitration in Sport (CAS) ruling expected Thursday before deciding whether a blanket Olympic ban on Russian competitors should be imposed. The IOC, which said it needed to study all "legal options," has now signaled it will take every day possible for one of the most important decisions in Olymnpic history. "We expect a decision within seven days on the participation of Russian competitors in Rio," IOC media relations chief Emmanuelle Moreau said. The IOC has already banned Russian Sports Minister Vitaly Mutko and all other ministry officials from the Rio Games and withdrawn backing for international events in Russia over the doping program revealed by Canadian lawyer Richard McLaren this week. McLaren, who produced a report for the World Anti-Doping Agency, said there was a "state-dictated failsafe system" of drug cheating. IOC president Thomas Bach called Russia's actions a "shocking and unprecedented attack on the integrity of sport and on the Olympic Games." WADA has called for Russia to be banned and are believed to have backing from the United States, Canada, Germany, Japan and other nations. "It's a complex issue to ban a country, but we're delighted to see they're considering it," New Zealand Olympic Committee secretary-general Kereyn Smith said. But some senior officials have expressed doubts whether the IOC wants to expel Russia. Dick Pound, an IOC member and former WADA president, said it was right for the IOC to take time to make a decision. But he added: "I do get the impression reading between the lines, however, that the IOC is for some reason very reluctant to think about a total exclusion of the Russians." Pound said an Olympic ban "would force Russia to acknowledge that the rest of the world is not prepared to play with them unless they change." Several national Olympic committees have also voiced support for Russia's case that it would be wrong to exclude Russian athletes who have not failed drug tests. Italian Olympic committee president Giovanni Malago said athletes were right to complain about Russian drug cheats. But he said none can say all Russian athletes are cheats and added: "In the public's imagination participation in the Olympics is for everyone. So I cannot imagine it without Russia." The Association of Summer Olympic Federations has also urged caution. The IOC said after Tuesday's executive talks it will "explore the legal options with regard to a collective ban of all Russian athletes" against "the right to individual justice." Evan Bach has called for a way to let clean athletes compete in Rio. It must first wait for the CAS ruling on an appeal by 68 Russian athletes against an Olympic ban ordered by the International Association of Athletics Federations. The IAAF suspended all Russian track and field competitors after an earlier inquiry, chaired by Pound, found widespread "state-sponsored" doping in athletics. While waiting for the legal opinions, the IOC has barred Mutko, a long-time ally of President Vladimir Putin, from the Rio Games. The IOC also ordered a disciplinary commission to look into the sports ministry's role in the drug cheating that included Russia's secret service swapping dirty urine samples for clean ones through a hole in a wall at the Sochi Olympics. The IOC said it will not grant any Rio accreditation "to any official of the Russian Ministry of Sport or any person implicated in the (McLaren) report." Mutko has denied any wrongdoing. He said he has suspended five top deputies, including his number two Yury Nagornykh, described as the point man for running the cheating scheme. The IOC executive also ordered a reanalysis of all samples by Russian athletes taken at the Sochi Olympics. That means several more weeks and months of inquiries. And the IOC said it would not give backing to any international sports events in Russia. It called on winter sports federations to "freeze" preparations for major events in Russia and look for alternative organisers. The McLaren case against Russia followed allegations made by the former boss of the Moscow anti-doping laboratory Grigory Rodchenkov who is in hiding in the United States and is wanted by Russia.