Police said Thursday that they had 21 suspects in custody for the alleged production and online distribution of toxic diet drugs.

Police discovered four workshops and nine distribution venues in the provinces of Zhejiang, Anhui, Heilongjiang and Guangdong, seizing 15,000 boxes of toxic capsules, according to the Public Security Bureau of Taizhou City, Zhejiang.

They also confiscated 2.8 million uncompleted capsules, 2.8 million capsule shells and 1,300 kg of raw materials. The seized goods have a street value of one billion yuan (145 million U.S. dollars).

Taizhou Police received information about the sale of toxic diet pills in September. An investigation showed the products contained sibutramine, a banned substance in China as it has been linked to cardiovascular issues.

The suspects allegedly sold the drugs through messaging service WeChat, and Taobao, the online market place.