The number of dead pigs found in a river which runs through Shanghai had reached nearly 15,000, officials and reports said Tuesday, as a newspaper claimed the government was concealing the true tally.

The images of dead pigs in China's commercial hub have proved a huge embarrassment for the city, which is seeking to become an international financial centre.

Shanghai city workers retrieved 369 bodies from the Huangpu River on Monday, bringing the municipality's total to 10,164 since the first were found earlier this month, the city government said in a statement.

Jiaxing in neighbouring Zhejiang province, whose farmers are accused by Shanghai of dumping the pigs into the river upstream, had found another 4,664 dead pigs, media reports said Tuesday.

But the Xiao Xiang Morning Herald, based in the central province of Hunan, quoted residents of Xinfeng in Jiaxing as estimating more than 10,000 pigs had been recovered from the water there.

Jiaxing has insisted it was not the sole source of the dead hogs.

The Shanghai government repeated on Tuesday that treated water was within government-set standards, and said no meat from the dead pigs had been found in the city's markets.

The scandal has highlighted China's troubles with food safety, adding the country's most popular meat to a growing list of food items rocked by controversy.

Animals that die from disease can end up in China's food supply chain if improperly disposed of, despite laws against the practice.

Samples of the dead pigs have tested positive for porcine circovirus, a common swine disease that does not affect humans.

At Wenling, also in Zhejiang, authorities said last week that 46 people had been jailed for up to six-and-a-half years for processing and selling pork from more than 1,000 diseased pigs.