Five restaurants are being prosecuted, while 30 others are under investigation, China’s food and drug administration said.
According to the Guardian newspaper, Shaanxi provincial police busted a noodle seller in 2014 after being alerted by a failed drug test. Seven restaurants were closed in Ningxia province in 2012 for using the additive and Guizhou province shut down 215 restaurants in 2004.
Hu Ling, the general manager of Huda, confirmed the company was under investigation, the Guardian said, and said it may have unknowingly sourced seasoning containing opiates. She declined to comment further.
It is unclear whether the opium added to the dishes would have been likely to cause addiction. They are readily available in China, but are illegal under the country’s food safety laws.
China has been at the centre of a number of food safety scares in recent years. In 2014, a Shanghai based supplier to a number of major Western brands was found selling unsanitary and expired chicken meat. While in 2009, the sector and nation as a whole was left reeling when baby milk, watered down and mixed with melanine, was said to be responsible for the deaths of at least six children.