Beverage producer Nongfu Spring, which had two of its products implicated in a recent arsenic scandal, questioned the original samples drawn for quality tests by authorities, saying the episode was manipulated.

"Even if the final test was accurate, it was absent of legitimacy I've no idea where the sample products came from," said Zhong Shanshan, chairman of Nongfu Spring, clamoring for legislation on inspection and testing institutions in an interview with Xinhua News Agency.

Haikou's Industrial and Commercial Administration Bureau on Dec 1 recalled its previous statement of toxic arsenic contamination in fruit juice products made by Nongfu Spring and Taiwan-based Uni-President after a re-test conducted by the testing center of the Chinese Academy of Inspection and Quarantine confirmed these products were safe for consumption.

The bureau issued a warning on Nov 24 stating Nongfu Spring's mixed fruit and vegetable juice and its Shuirong C100 grapefruit juice made on June 27 and Aug 16, respectively, along with Uni-President's peach juice Peachate contained excess amounts of the toxic chemical arsenic after a test by the Hainan Entry-Exit Inspection and Quarantine Bureau.

All implicated products sold in the city of Haikou were pulled off the shelves immediately, which Nongfu Spring estimated will cause the company to lose over 1 billion yuan.

"We set up an investigation group on Dec 2 to start looking into the detailed law enforcement procedures of the local industrial and commercial watchdog," said Huang Chengmo, bureau chief of Hainan province's industrial and commercial watchdog, the superior counterpart of the bureau in Haikou city.

China's Food Safety Law stipulates that the health administration authorities, rather than the industrial and commercial watchdog, should be responsible for announcing food safety risk warning information.

Xinhua quoted Zhong as saying that the entire test procedure was "not legitimate and was masterminded", without elaborating who may have been behind the scenes.

According to a survey conducted by major portal Sina.com, more than 88 percent of about 124,000 respondents said that Haikou's industrial and commercial authorities should compensate the companies and make a public apology, while 86 percent said that those responsible "should be severely punished, even dismissed".