SHENZHEN, April 13 (Xinhua) -- A shipment of bear gallbladders has been seized by customs in south China's Shenzhen city, local customs said Friday.

A customs official said that animal organs were found in a vehicle entering Shenzhen in south China's Guangdong Province from Hong Kong on April 11. The organs, which were not declared to customs, were wrapped in thick paper.

Preliminary investigation showed there were 12 whole gallbladders and part of a bear gallbladder, weighing nearly 300 grams.

Customs has turned the case over to the anti-smuggling department.

It is forbidden to trap, kill or trade brown or black bears, according to the Convention on International Trade in Endangered Species of Wild Fauna and Flora. China also stipulates that permission is required to import and export endangered species.

Travellers are also prohibited from taking or mailing ordinary animal products to China, said the customs.