A 20-member criminal gang that turned a profit by manufacturing and selling "gutter oil" has been busted in east China's Zhejiang province, a local procuratorate said.

The Wucheng district procuratorate in the city of Jinhua said Saturday that it has ratified the gang members' arrests after police evidence showed that the gang, led by Li Weijian and his wife Xu Xiaoqing, had used kitchen waste and discarded animal fat to illegally produce and sell cooking oil since 2005.

Prosecutors said in 2011 alone, the gang pocketed over 10 million yuan (1.6 million U.S. dollars) from the illegal business.

The gang sold the oil to cooking oil wholesalers and food processing plants in Shanghai, Chongqing and Jiangsu province.

The Ministry of Public Security said in April that it has stepped up a crackdown on underground workshops that produce gutter oil. The oil has been deemed unsafe for consumption, as it may contain carcinogenic substances.