Police in Hunan Province have arrested seven people and detained one for manufacturing and selling a new type of banned food additive clenbuterol - also known as "lean meat powder."

The substance discovered in Hunan in March - known as phenylethanolamine - was recorded for the first time in China. About 2.5 tons of feed containing the additive has entered the local market.

During a random check, local authorities found pig feed produced by two factories, in Fujian and Guangdong, containing clenbuterol.

According to police, their investigation led to the Longhai Haixin Feed Mix Co in Fujian, which supplied materials to the two factories, and five people from the company were arrested, Xinhua news agency reported yesterday.

Two businessmen from Zhejiang Province were also arrested, after they were allegedly found with 1,500 kilograms of feed containing the banned additive.

Police allegedly discovered another 1,500 kilograms of feed containing the new additive through a professor at Zhejiang University who is now under detention.

The eight people were in one manufacturing group and three sales groups, according to the report.

The Ministry of Agriculture has banned phenylethanolamine from animal feed.

In April, police in Hunan caught 16 suspects allegedly manufacturing and selling the clenbuterol worth 30 million yuan (US$4.65 million).