After plucking 5,916 bloated dead pigs, local officials expect to find more carcasses in the Huangpu River which flows through the center of Shanghai -- a source of the city's drinking water.

Local authorities say that Shanghai's water quality was "normal" and that "no pollution has been found," according to state-run newspaper Shanghai Daily on Wednesday. The city's water authorities say they are increasing the number of quality checks, removing the dead pigs while they are further upstream and working to ensure water quality, according to the local Chinese newspaper.

Meanwhile, some in China expressed skepticism on the popular microblog service, Sina Weibo.

"Since apparently, the water has not been contaminated, big leaders, please go ahead and have the first drink," wrote Weibo user, @_Nina_Burbage.

How thousands of swollen dead pigs got to the river remains unclear, although there have been some clues.

This week, sanitation workers, clad in masks and plastic suits, fished the bruised pig bodies from the river. The pink, decomposing blobs surfacing in the Huangpu River wreaked foul odors and alarmed residents.

"There were dead pigs all around and they really stunk," one local resident told CNN. "Of course, we're worried, but what can you do about it? It's water that we have to drink and use."

A Weibo user, @Muyunsanjun2011 asked: "Since when is finding dead rotting pigs in a major river not a public health problem? Answer: When this happens in China. The Shanghai Water Authority insisted on Monday that despite the large number of dead pigs, tap water taken from the Huangpu River in Shanghai still meets state water quality standards."

If the water treatment process is very effective and can handle the sudden shock loading of contaminants, it's possible to minimize the impact, said Julian Fyfe, a senior research consultant specializing in water quality at the University of Technology Sydney.

But he added: "Most treatment plants would not be designed to accommodate that level of shock loading," about a situation involving 6,000 dead pigs floating in a river. "It's such an unsual event."

Fyfe spoke in general terms about water quality issues, as he is not involved with Shanghai's water treatment.

"If they are chlorinating heavily, which a lot of places may do, especially if they've got a very polluted water body to start with, then the effects could potentially be small," Fyfe said.

Dead pigs which have been sitting in the water for days, would leak blood, intestinal fluids and other pollutants, which could alter the taste and color of tap water.

Many residents have begun drinking bottled water in fear of contamination, according to the Global Times, a Chinese newspaper.

The agricultural commission in China said it had tested organ samples from the pigs and the results suggested the animals had contracted a type of porcine circovirus.

On Tuesday, national officials acknowledged the pig incident in a press conference Tuesday.

"According to monitoring statistics, there's no evidence to show that there's an outbreak of any major animal epidemics," said Chen Xiaohua, the national vice minister of agriculture. "But in the meantime, the incident shows how we need to improve our work in the future."

Some Chinese netizens took a humorous approach lampooning the situation. A movie poster for "Life of Pi" was doctored and replaced with "Life of Pigs" with the main character's boat filled with dead pigs, and the water dotted with the bruised corpses.

One weibo user, @Fujiadiandianxiaoya joked: "I finally figured out why drinking boiled water makes me gain weight -- because it is in fact pork soup!"

Local authorities say they're looking into how the pigs ended up in the river.

One possible factor, reported in the Chinese media is a disease that had killed thousands of pigs in a village south of Shanghai. Officials in Jiaxing had blamed the dumping on some "local pig farmers who lack awareness of laws and regulations."

The labels in the ears of the pigs found in the Huangpu River indicate they could have come from Jiaxing City, according to Xinhua, the Chinese state-run news agency. But officials say the tags only indicate place of birth, so the pigs could've come from elsewhere.

Another official told the Shanghai Daily that the water doesn't necessarily flow from Jiaxing to Shanghai.