CHINA: A police crackdown on illegal pork sales has resulted in mass dumping of dead pigs in Shanghai's river and more than 2800 carcasses floated into the city in just one day.

The effort to keep infected pork off dinner tables may be fuelling new health fears, as Shanghai residents worry over contamination to the city's water supply, although authorities say no signs have been detected.

They have been pulling out the swollen and rotting pigs, some with internal organs visible, since Friday.