Staff of Shantou customs in South China's Guangdong Province quarantine corn seeds in containers. (Photo: Shantou Customs)

Chinese customs on Saturday returned 46 inbound containers carrying transgenic corn seeds, originally from the US, media reported.

Customs officials in Shantou, South China's Guangdong Province, found grass, live insects and 50 kilograms of corn seeds during an inspection of the mostly empty containers on November 27, which were transferred to Shantou after unloading US corn in the island of Taiwan, the Guangzhou Daily reported on Monday.

It was confirmed after testing that the corn seeds were genetically modified.

In order to prevent genetically modified seeds from entering China without approval - which could endanger China's agriculture, animal husbandry and grain production -  customs officials in Shantou have ordered relevant enterprises to return the containers in accordance with the customs regulation on the inspection and quarantine.

The individual in charge of Shantou's customs said the containers, as important means of cargo transportation, could easily deposit a variety of plant seeds, pests and soils during the process of cross-border transportation, and that they could lead to the cross-border spread of epidemic diseases.