Following pork, chicken and duck, Zhang Jinmei has erased mutton from her family's menu because of reports that the lamb sold in the city's produce markets may turn out to be rat, fox or mink.

Over the weekend, the city's food safety commission office said it will investigate where the fake mutton has been sent after police broke up a criminal ring selling it from uninspected meat in Wuxi, Jiangsu province. The products are believed to have trickled down to markets in Shanghai.

Earlier, families in much of China removed poultry from their menu because of the spread of the potentially lethal H7N9 bird flu virus. Pork sales were also briefly hit after more than 10,000 pig carcasses were found floating down the main river through Shanghai in March.