China will inspect its aquaculture in coastal areas after some turbot were found to contain excessive amounts of a carcinogenic medicine in Shanghai, the State Food and Drug Administration (SFDA) said on Friday.

During its latest inspection, the Shanghai food and drug administration detected excessive medicine residue in all 30 samples of turbot.

Due to their poor disease resistance, fish are sometimes fed with large quantities of banned medicine, leaving behind excessive medicine residue.

"Though these medicines cause no harm to the human body in the short term, they are probably carcinogenic when taken in large quantities," an unnamed expert said.

The SFDA has urged local offices and authorities in Shandong, Jiangsu, Hebei, Zhejiang, Fujian, Guangdong, Liaoning and Tianjin to conduct inspections of its aquaculture and closely monitor the situation.

The Shanghai food and drug administration issued an alarm on Friday, warning people to be cautious when buying and eating turbot.

The turbot has developed quickly in China since it was introduced from Europe in the 1990s.

Editor: Yan