African donkey hides and pet food were among the smuggled products recently intercepted by customs authorities in Guangzhou, capital of south China's Guangdong Province.

Guangzhou Customs authorities said Wednesday they had detained 13 suspects in connection to a smuggling case worth about 82 million yuan (12 million U.S. dollars).

About 24 tonnes of African donkey hides, 55 tonnes of pet food and 122,881 bottles of foreign liquor were intercepted from 21 containers smuggled by rail. Some of the pet food neared the expiration date and some donkey hides were rotten due to the long transport time.

Authorities said that if the rotten donkey hides was made into ejiao, or donkey-hide gelatin, it would pose hazard to public health.

Donkey-hide gelatin, known as ejiao in Chinese, is a kind of traditional Chinese medicine and health food made by boiling the donkey's skin and refining the results into a tonic. Ejiao is mainly taken by women who suffer from anemia, dry coughs or dizziness. The name was coined in Dong'e County in east China's Shandong Province, where it was originally produced.

Further investigation is underway.