The company plans to invest $4 billion in China from 2012 to 2014 and open a plant in Shijiazhuang, capital of North China's Hebei province.

Su Yan, a member of the board of directors of the company's Shanxi branch, said the company took time to investigate and verify what had really happened in the case. That's why, he explained, the company changed its course from first denying media reports that said Coca Cola drinks contained unusually high amounts of chlorine to agreeing to replace the products.

The company angered many people when it issued a notice on its Sina Weibo micro blog on April 2 offering to replace the products in question but not to provide reimbursements to those who had bought them.

A whistleblower in the Shanxi factory was the first person to allege to media outlets that drinks made there had been tainted with chlorine. When asked by reporters at the Friday news conference if the employee had been punished, Su said he had no knowledge of there being a whistleblower inside the company.

Sun Wei, Coca Cola's legal advisor in China, said the contamination occurred in February, when water containing small amounts of chlorine used to clean bottles was mixed with water that ultimately went into beverages.

Sun said the affected batches only contained trace amounts of chlorine, less than the 0.005 milligrams per liter allowed by China's national standard for purified water.

Chlorine is commonly used to kill bacteria but can be hazardous in large amounts.

Liu Wenjun, director of Tsinghua University's institute for drinking-water safety, said Chinese standards say tap water should contain no more than 4 milligrams of chlorine per liter.

Contact the writers at sunruisheng@chinadaily.com.cn

and liyao@chinadaily.com.cn