The China Food and Drug Administration tested 35 restaurants and snack bars across the country last week. The owners of 25 of these were subsequently transferred to the public security department for criminal investigation, and five will be prosecuted, said the CFDA. The remaining 10 restaurants are still under investigation by the administration.
According to Xinhua, China’s state news service, it is an "open secret" that poppy-derived powder is being used as a "secret ingredient" at some small restaurants in dishes or hotpots to improve the taste.
However, the ingredient is controlled as a narcotic under the belief that long-term consumption of poppy capsules can lead to addiction, damage the nervous system and cause chronic intoxication.
Adding poppy capsules to food is prohibited by China's food safety law, and the government has taken a "zero tolerance" policy toward violations.
Last June, two managers of a restaurant in Hubei province were arrested on suspicion of adding opium poppy products to dishes.
The sting is part of a visible move over recent month by food authorities to intensify their supervision and inspection of restaurants and impose tougher penalties on violators.