Chinese athletes are swearing off meat ahead of the London Olympics out of fear that domestic pork, beef and lamb could contain substances banned under anti-doping rules, a report said Wednesday. They are instead relying on protein powder and fish to meet the high protein needs of top-class athletes, the Yangtze Evening News reported, as China goes after another successful haul of medals. At least 196 competitors under China's National Aquatics Centre, which governs swimming, diving and other water sports, have been off meat for the past 40 days, the report said. The London Games are 100 days away. China's food production industry is notorious for frequent scandals involving producers who illegally or excessively use various additives in the raising of livestock. Authorities are particularly concerned that athletes could unwittingly consume clenbuterol, which is banned for food production in China but has been found in contaminated pork. Clenbuterol can speed up muscle-building and fat-burning to produce leaner meat but has also been used by athletes as a performance-enhancer. It is banned by the World Anti-Doping Agency. China's 2008 Olympic women's judo gold medallist Tong Wen was banned in 2010 for two years for testing positive for the substance. Chinese media reported earlier this year that national sports authorities had banned athletes from consuming meat outside of state training facilities. Officials with the National Aquatics Centre and the sports ministry could not immediately be reached for comment. Authorities have tightened supervision at training centres to ensure no clenbuterol-tainted food slips through and have launched checks of local produce near such centres, the Yangtze Evening News said. "The kitchen is probably the most secure place at the Jiangsu province sports bureau... locks are installed on entry doors and only (kitchen) workers can enter," it said.