At least 70 people have fallen ill after eating pork products contaminated with an illegal animal feed additive, the BBC reported, citing state media. The victims from Guangdong province were treated for diarrhea and stomach pains. Three people are still in hospital. The tainted pig organs contained the steroid clenbuterol, which is used to prevent animals gaining fat. The meat was produced on farms in Hunan province. Three people have been detained by police on suspicion of raising contaminated pigs. Clenbuterol is banned as a food additive because it can be fatal for humans. The drug is given to treat asthma and has been used illegally by athletes to build muscle.