He was responding to a question by Democratic Progressive Party Legislator Ho Hsin-chun on the issue of leanness-enhancing drug residues found by a private laboratory in some samples of locally produced pork products, reports Focus Taiwan.

Mr Chen said the government is concerned about the situation and has tightened its monitoring measures to ensure the safety of pork.

The initiatives, announced Monday, include stricter checks on pig farms, slaughtering facilities, processing factories, traditional markets and other places, Mr Chen said.

As of today, hog farmers will also be required to provide a statement that they are not using leanness-enhancing drugs in pig rearing.

Last week, the government conducted tests on pork products sold nationwide at supermarkets, hypermarkets, restaurants and traditional markets, but found no problems, Mr Chen said.

Asked by Mr Hsin-chun to explain the difference in the results obtained by the private lab, Mr Chen said the government collected more samples nationwide and that its tests for leanness enhancers were all "negative."

He admitted that there is pork containing leanness-enhancing drugs on the local market, but stressed that the government is taking new steps to ensure the safety of pork products.