A court in east China has jailed six butchers for selling pork tainted with the carcinogenic chemical clenbuterol, which is fed to pigs to produce leaner meat, state press reported Wednesday.

The clenbuterol scandal is just one of numerous food safety issues to surface in recent years in China, ranging from rice contaminated with heavy metals to dyed buns and a tainted milk scandal.

A court in Nanjing, the provincial capital of Jiangsu province, convicted the six butchers of harming public safety on December 13 and sentenced them to up to four years in prison, Xinhua news agency said.

They were also each fined up to 50,000 yuan ($7,900), the report added.

The defendants confessed they sold the meat even though they knew it was tainted with the chemical, it said.

The tainted pork scandal surfaced in March after traces of clenbuterol were found in live pigs in numerous slaughter houses in agricultural producing regions.

By the end of November, at least 113 people including 77 government employees, had been jailed in connection with the scandal in Henan province alone, Xinhua said.

On Sunday, China's food safety watchdog said it found high levels of aflatoxin, a carcinogen, in milk produced by the Mengniu Dairy Group, one of the nation's top dairy producers.

Milk was also at the centre of China's biggest food safety scandal in 2008 when the industrial chemical melamine was found to have been illegally added to dairy products to give the appearance of higher protein content.

At least six babies died and another 300,000 became ill after drinking milk tainted with melamine.

In May, the country's top court ordered that capital punishment be used for food safety crimes that result in fatalities.