Toxic waste from a copper mine in China has contaminated a river, causing the death of millions of fish, authorities said Monday.

About 1.89 million kg of dead fish were found lying in the Mianhuatan reservoir in China's Fujian province, after being poisoned from copper waste released by the Zijinshan copper mine, Xinhua reported.

The mine is owned by a Hong Kong-listed company.

The foul odour of dead fish can be smelt from even 10 km from the reservoir, villagers complained.

The government has mobilised civil servants, officers and armed police personnel as well as local villagers to help net the dead fish.

'The county government has issued a circular asking residents to turn in poisoned fish for collective disposal. Villagers will receive three yuan ($0.4) for each kg of dead fish turned in,' an official said.