A technician is getting pig urine samples to test for clenbuterol.

The government will launch a one-year campaign to crack down on illegal additives in pig feed that are believed to be harmful to humans, the Ministry of Agriculture (MOA) said on Monday.

Earlier this month, traces of clenbuterol, a pig drug banned for use in China, were found in pigs raised in central China's Henan Province, and a subsidiary of Shuanghui Group, China's largest meat producer, was caught using tainted pork in its meat products.

Those who deliberately?produce, sell and use?clenbuterol?in pig food?would be severely punished, according to MOA.

The authorities would also take measures to block tainted pork from entering the market and monitor pig-raising and other steps in pork supply chains, such as purchasing and slaughtering, to ensure safety of pork products.

It was reported that in Henan Province's Mengzhou City, Qingyang City, Wenxian County and Huojia County, using clenobuterol to raise pigs is an open secret.

According to an announcement of the Henan provincial government on Monday, 12 officials have been delivered to judicial departments for involvement in the scandal and another 41 are being probed.

Clenbuterol is a chemical that can prevent pigs from accumulating fat. It is banned as an additive in pig feed in China because it can end up in the flesh of pigs and is poisonous to humans if ingested.