Consumers who were sent into a panic recently after a banned and hazardous additive was found in pork are facing up to the fact that the same substance may also be tainting lamb.

The latest food safety scare flared when clenbuterol was allegedly detected in live sheep that had been sold in North China.

The substance had previously been fed to pigs by farmers because it promoted muscle and reduced fat, bringing a higher price for pigs, even though it risked the health of consumers.

In the latest scandal, 198 sheep awaiting slaughter and processing in Hebei province were suspected of having been fed the banned additive, the food inspection authority in Hebei said on Sunday.

The sheep had previously been bought from Qingyun county in Shandong province.

The authority said a spot check indicated that two of the sheep tested positive for clenbuterol. All 198 animals were subsequently impounded.

Two farm managers were taken into police custody and further investigation is under way, Qingyun county government said on Monday.

The government also dispatched 10 work teams to carry out strict checks at sheep farms in the county.

The results of those checks were not known by press time on Tuesday.

The case provoked panic among the public once again following the earlier incident in which Jiyuan Shuanghui Food Co Ltd in Central China's Henan province was found in March to have purchased pigs that had been fed the banned additive.

The substance can speed up the growth of muscles and burn fat, resulting in leaner meat but has been banned in China as an additive in animal feed since 2002 because it can cause people to suffer from nausea, headaches, limb tremors and even cause cancer.

The scandal last month caused huge recalls of meat products processed by Jiyuan Shuanghui in supermarkets across the country.

Li Bo, a staff member from Beijing's animal health inspection institute, told China Daily on Tuesday that most of the capital's lamb came from the Inner Mongolia autonomous region and none had been found to contain clenbuterol.

"In Beijing, all livestock, such as pigs and sheep, must be processed at designated slaughterhouses and undergo strict tests," he said.

But Wang Jiankun, a Beijing resident, said he plans to eat more vegetables and less meat following the health scares.

"It's really terrible that they add so many additives to livestock feed," he said. "I don't know which meat product will test as poisonous the next time so the best thing to do is refuse to eat it."

Liang Haoyi, a senior researcher at the China Animal Agriculture Association, said the flurry of cases connected to illegal additives in livestock feed shows that the government should bring in more effective measures to prevent the supply of such toxic ingredients.

"At present, major checks only target livestock farmers and slaughterhouses," he said. "More investigations should be focused on where farmers can buy the toxic additives."