BEIJING - At least 70 people in southern China fell ill after eating pig organs contaminated by a banned animal feed additive, news media said Monday.

Three people were in the hospital, while the rest were discharged after being treated for stomach aches and diarrhea over the weekend, China Daily newspaper said.

The pig organs tainted by the steroid clenbuterol were sold last week in markets in Guangzhou, the capital of Guangdong province, it said.

Clenbuterol helps to build muscle and is frequently used as an illegal performance-enhancing drug by track and field athletes.

China has banned its use as a pig feed additive.

Authorities have detained three people involved with raising and selling the pigs, which came from farms in the neighbouring province Hunan, China Daily said.

In 2006, more than 300 people in Shanghai were taken to hospital after eating pork and pig organs tainted with clenbuterol.

Last August, hundreds of thousands of children were sickened after drinking tainted milk, which was also blamed for the deaths of six babies.