More than 900 dead pigs have been retrieved from Shanghai's Huangpu River as of Saturday afternoon after a large number of bodies were found floating in the water, local authorities said.

The dead pigs were spotted in the Songjiang section, the upstream of the Huangpu River and a drinking water source for Shanghai residents, according to the city's water supplies bureau.

The bureau said the water quality has not been affected. However, to ensure tap water safety, local environmental protection and water supplies authorities have beefed up quality examination at the water intakes as well as the whole water disinfection process.

The Shanghai Agriculture Committee have carried out bio-safety treatment on the retrieved dead pigs. It is investigating where the dead pigs may have come from.

The committee said so far it has not received reports of animal epidemic outbreaks in the city.

Local authorities are still retrieving dead pigs to avoid water contamination.