China's top inspection and quarantine authority warned on Thursday that mitten crabs from Germany are not qualified to be imported without going through quarantine after thousands of such crabs were ordered from an online shopping site.

The authority has not received any application for risk assessment and quarantine from German authorities for the crabs, the General Administration of Quality Supervision, Inspection and Quarantine said on Thursday.

The mitten crabs were put on sale by a Suzhou-based e-commerce food company, Dadiyuansheng e-commerce co, on Sunday at its online store and juhuasuan.com, a group buying site under Alibaba group, China's largest e-commerce company.

Labeled as "German wild crabs from the unpolluted Elbe" and priced from 199 yuan ($32.50) to 399 yuan a pack depending on the weight and number of crabs contained, the products attracted tens of thousands of orders within less than a week and about 300,000 German crabs had been ordered online as of Thursday.

The quarantine authority said imported crabs that have not been quarantined could carry risks of disease as the species has been in German waters for nearly 100 years and mutation is possible.

The authority has already conducted an emergency discussion with the group shopping site, asking them to come up with a "proper" solution to the problem and an explanation to the public.

Responding to the authorities, the group buying site juhusuan.com said on its micro blog that mitten crabs would "definitely" go through customs clearance in both Germany and China.

"The sales of Germany mitten crabs are through a customer to business model. And, quite different from traditional export and import trade, the model gathers orders online and then stocks up for sales," the site said in a micro blog message.

It added that the mitten crabs could not yet be declared at customs because the seller is still stocking up on them.

Jiao Jian, CEO of Dadiyuansheng, said on his micro blog that he believed the sales of mitten crabs were disallowed because it would affect "certain domestic crab industries". Jiao said the crabs would be imported live.

A staff member of the Crab Association of Yangcheng Lake, the place widely considered to produce the best crabs in the country, told China Daily he doesn't think the German variety would "have any impact on the crabs that have been popular in the market and craved like hotcakes for decades".

In a previous interview with Shanghai-based Oriental Morning Post, Jiao said his company has eyed the domestic market since last autumn. He claimed the German crabs he sold are provided by local fishing companies "after tough negotiation" because no companies in Germany export to China.

The lure of mitten crabs from Germany has proved hard to resist for some Chinese consumers.

"I am just curious what the foreign cousins of Chinese crabs taste like," said Zhu Xinli, a 29-year-old housewife in Shanghai. She had just purchased a 399-yuan pack of the German crabs from the online store.

"I believe the German waters will be less polluted than ours," said Zhu, adding she wouldn't withdraw her order as long as the German crabs can arrive in China.

Contact the writers at xujunqian@chinadaily.com.cn and xuwei@chinadaily.com.cn