BEIJING - Sweeping spot-checks of thousands of pigs in Henan province found only a very small minority had been fed with the banned substance clenbuterol.

The Ministry of Agriculture said on Tuesday that the test results suggested that a recent health scare involving tainted meat may have just been an isolated case.

The ministry posted an announcement on its official website, saying only 134 pigs out of 310,000 tested in the province were found to have been fed the illegal additive.