Municipal food safety authorities were still waiting to find out Sunday where rat and other meat sold as lamb ended up in the city after the Ministry of Public Security disclosed that more than 10 million yuan ($1.62 million) worth of the meat was sold in Shanghai and Wuxi, Jiangsu Province.

The Shanghai Municipal Food Safety Committee was still waiting to hear back from the ministry Sunday, said Gu Zhenhua, the committee's vice director. "We do not know where the meat has been sold," he told the Global Times.

The ministry announced Friday that an illegal group has been selling rat, fox and mink meat posing as lamb since 2009. Police confiscated more than 10 tons of the meat after they raided about 50 locations in February scattered across Shanghai and Wuxi.

The meat was sourced from Shandong Province. It was mixed with gelatin, carmine and nitrate to make it look and taste more like lamb, according to the ministry.

The committee had not known about the problem until the ministry made its announcement, Gu said.

"We are currently carrying out food inspections at local markets," Gu said.

Li Shuguang, a food expert from Fudan University, speculated that the fox and mink meat could have originated from farms in Shandong that raise the animals for their fur, according to a news report broadcast on Shanghai Television Station.

That would be dangerous because a study by a medical school in Shandong found that mink meat from a local farm contained excessive levels of bacteria hazardous to humans. It also found that a large number of the mink raised on the farm died from infection.

It is illegal to sell rat, fox and mink meat in China because there are no food inspection standards for them, said Hou Caiyuan, a professor specializing in food safety from China Agricultural University.

"There are serious holes in the government inspection process for meat products," Hou told the Global Times. "The criminal group carried the illicit business for more than four years, and it wasn't the food watchdog, but the police, who discovered the problem."

Under the ordinary inspection process, there isn't a test to determine if a kind of meat is really what it claims to be, said Sun Shuxia, the director of the Food Nutrition Safety Committee of the China Health Care Association.

"For large slaughterhouses and supermarkets, managers usually keep invoices and other documents that show where the meat originated so they can trace its source. The real problem lies with the small street vendors and restaurants that buy their meat from unregulated food markets," she told the Global Times.