Seven suspects have been detained on suspicion of producing harmful drinks in Foshan, South China's Guangdong province, the Foshan Police Department announced on Wednesday.

Shine Bee drink (also known as Kawa Chaoyin in Chinese), was a popular alcohol-substitute drink online produced by the Wei’erle company in Foshan, which was distributed by Szechuan Shizang Industrial Management Company.

The drink was made from a type of pepper from South Pacific Island countries and appeared on the market in 2015. A controlled drug, γ-hydroxybutyrate, a first class psychoactive drug in China, had been found in the drink by Foshan Food and Drug Administration. The production line for the drink has since been shut down.

An official at the Guangdong Provincial Public Security Department said many complaints had been received about the drink this month.

"We knew that the product had been sold in 20 different provinces over the whole nation. The Shine Bee drink indeed contains illicit drugs after inspection of the product", Beijing Youth Daily quoted the official as saying.

The drink was sold mainly in southeastern China in Guangdong province. But many agents sold the drink online through social chatting tools, such as WeChat.

The case is still under investigation.