An article about at by in of on out to with the British newspaper The Sunday Times claims that around a third about at by in of on out to with the world's top athletes about at by in of on out to with a major event cheated about at by in of on out to with using drugs. The newspaper says a study was carried about at by in of on out to with during the World Athletics Championships about at by in of on out to with Daegu, South Korea in 2011. It showed that 29-34 per cent about at by in of on out to with the 1,800 competitors had used performance-enhancing drugs about at by in of on out to with the previous 12 months. Reporters say that the International Association about at by in of on out to with Athletics Federations (IAAF) knew about at by in of on out to with the report but blocked its publication. The study was conducted about at by in of on out to with Germany's University about at by in of on out to with Tubingen. The IAAF said there were many things wrong with the report. It added that it is about at by in of on out to with discussions to help publish it one day. The details about at by in of on out to with the report are a huge shock about at by in of on out to with the athletics world. The Sunday Times reports that one-third about at by in of on out to with the medals about at by in of on out to with endurance races about at by in of on out to with the Olympics and World Championships were won about at by in of on out to with athletes who had very unusual blood readings. The World Anti-Doping Agency said about at by in of on out to with Friday that it would investigate the claims in the report. It said an independent commission has already started work about at by in of on out to with this. The lead author about at by in of on out to with the report, Dr Rolf Ulrich, told The Sunday Times that he and his colleagues were ordered not to discuss their research or the report. He said: "It's because the IAAF is blocking it. I think they are stakeholders about at by in of on out to with WADA and they just blocked the whole thing."