Dairy products containing ingredients imported from New Zealand and potentially contaminated with a botulism-causing bacteria have been sold on the Chinese market, as authorities issue bans on the products amid company recalls.

However, the importers, which imported the tainted whey protein via global dairy giant Fonterra, claimed that the products are safe because of the way they are manufactured.

The Xinhua News Agency Sunday quoted Zong Qinghou, board chairman of the Wahaha Group, as saying that the company had imported around 14.5 tons of tainted whey protein to process its dairy products, and the products are almost sold out after entering the market from October 2012.

The quality watchdog in Shanghai on Sunday revealed that the largest importer, French food group Danone's baby milk subsidiary, Dumex, had imported 208.55 tons of whey powder of which 105.45 tons had already been used to make 726.6 tons of dairy powder.

Of that dairy powder, more than 420 tons have been sold, Xinhua reported.

Shanghai Tangjiu, a Chinese agent for Fonterra, Sunday said in a statement that 25 kilograms of raw materials have been used for the production of a milky beverage sold by Coca-Cola's China branch, leaving 4.775 tons in the warehouse.

Coca-Cola, Wahaha and Dumex all said they are recalling the products from the market.

The series of responses came on the heels of Fonterra's Friday announcement that some of its whey protein, a product used in many products including baby formula and sports drinks, produced in May 2012, was found to be contaminated with clostridium botulinum, which can cause botulism.

"Half of the imported milk powder in China is from Fonterra, and almost all the big dairy producers are its clients," Wang Dingmian, a dairy industry expert, told the Global Times Sunday.

Data from the General Administration of Customs in July indicated that in the first half, China imported 445,000 tons of milk powder, and New Zealand provided 83.3 percent of the total amounts.

China's quality watchdog Sunday said that it had ordered importers to withdraw any contaminated products and called on quarantine officials to step up inspections of dairy products from New Zealand.

New Zealand Trade Minister Tim Groser told local media that Chinese authorities have stopped all imports of New Zealand milk powders from Australia and New Zealand, Reuters reported, though no official announcements from China have confirmed that.

Meanwhile, Wahaha said in an announcement posted on its website Sunday that routine factory tests of products that used Fonterra's whey protein group did not find any remains of such bacteria.

The company also noted that because the bacteria are heat sensitive, the risk they made it through to products are low given the high temperature sterilization process.

On Sunday night, Fonterra confirmed on its website that the products of three of its customers that received whey protein concentrate, including Wahaha and Coca-Cola, are safe to consume because of the way they are manufactured.

Fonterra's actions have raised doubts among the public as it revealed that the bacteria were first identified in a product in March, but only made public the findings last week.

Zhang Yongjian, a food and drug expert with the Chinese Academy of Social Sciences, told the Global Times Sunday that the producer should have stopped selling the products right after it conducted the quality examination in March. "The earlier the company stops selling the product, the lower the risk to consumers," Zhang said.

Wang also said that the importers should clarify the exact date or the batches of their products produced with tainted ingredients to better inform consumers.

Bao Xiaohe, a new mother in Beijing, told the Global Times that she will "remain on high alert" regarding the quality of milk powder and would not feed it to her baby as she was worried about quality issues.