The amount of unsafe foreign dairy products seized during importation is on the rise in recent months amid the unalleviated public concern over unsafe milk formula in the country.

A report on substandard imported food and cosmetics released by the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) over the past weekend said a total of 402 tons of unsafe dairy products were returned or destroyed in June.

The amount far outnumbers the 22 tons in April and 27 tons in May. It is also 10 times more than the 40 tons of unsafe dairy products seized in June 2009, according to the AQSIQ.

Among the products seized in June this year, 401 tons were milk formula, making up 99.8 percent of the total.

Data showed the problematic milk formulas were from countries and regions including New Zealand, Singapore, United States, Australia, France and Taiwan.

Problems with the products included the presence of enterobacter sakazakii, a bacteria that can lead to infection, as well as excessive amount of nitrites, zinc and total bacterial count, the AQSIQ report said.

Hunan Huayi Trading Co Ltd topped the list as the importer of 201 tons of unsafe milk formula from Australia in June and 131 tons from France in March.

The company is listed on hncredit.gov.cn, a website run by the Hunan Enterprise Information Management Bureau, as a registered foreign trade cooperation starting June 2003.

Animal byproducts are on the company's listed scope of business.

Company officials could not be reached for comment on Wednesday.

Wang Dingmian, former chairman of the Guangdong Provincial Dairy Association, said the rising number of unsafe imported dairy products is mainly due to the increasing domestic demand for foreign dairy products.

The latest figures available from China's General Administration of Customs show that in the first five months of this year, China imported 310,000 tons of dairy products, up 28.6 percent year-on-year.

"The amount of imported milk formula has been increasing at many ports around the country, including Guangzhou, Tianjin, Qingdao and Shanghai, resulting from the increasing demand from middle-end consumers and food companies," Wang said.

Foreign companies most likely did not deliberately dump unsafe products to China, because "once the products were tested unsafe, the companies had to pay the bills to call back and destroy them."

"But a skyrocketing demand could open a door for unsafe products to enter the country," he said, adding that consumers should avoid blind belief in foreign dairy products.