A ban on State purchases of vegetable oil processed from imported rapeseeds is to protect domestic farmers' economic interests and does not mean the government is concerned about the safety of genetically modified food, an industry insider said.

"Many enterprises have a growing interest in purchasing imported rapeseeds since the price in the international market has been lower than the domestic price in recent years. So the country imposed the ban this year to protect farmers' interests," a China Grain Reserve Corp official who declined to be named said on Tuesday.

The company's routine checks before purchasing rapeseed oil was mainly for oil content and impurities. But testing for GM ingredients was not part of the inspection, he said.

The company does not yet have the ability to test for GM ingredients, he added.

The officials' comments followed a statement on the company's website on Monday that about 1,477 metric tons of the oil, purchased from two of its entrusted enterprises in Hunan and Hubei provinces, were processed from imported GM rapeseeds.

The GM rapeseed oil has been removed from State reserves, it said.

The website statement came in response to recent media reports that some rapeseed oil delivered to the State reserve was processed from imported GM rapeseeds, which violates the country's grain-purchase policies.

The country commissioned the purchase of about 1.67 million tons of rapeseed oil from the domestic market this year. But some enterprises that were commissioned to buy the oil bought imported GM rapeseeds since they were cheaper than regular, domestically planted rapeseeds, 21st Century Business Herald reported on Monday.

The GM rapeseeds tainted the State reserve, which is responsible for storing domestically made non-GM rapeseed oil. The GM rapeseed oil in the State reserve likely would have been consumed as non-GM products in the domestic market, the report said.

"The majority of cooking oil in the domestic market contained GM ingredients, but many such products were without clear labels," said Lu Bu, a researcher on agricultural resources and regional planning at the Chinese Academy of Agricultural Sciences.

As much as 70 percent of the domestic supply of cooking oil relied on imported agricultural products after processing due to the country's low self-sufficiency, and about 80 percent of those imported products were GM soybeans, he said.

"But many oil enterprises have not clearly labeled their products as containing GM ingredients partly because of current widespread public concerns about the safety of GM food," he said.

Huang Dafang, a former member of the biosafety committee in charge of agricultural GM organisms, said consumption of GM products that aren't clearly labeled as such does not pose a public health risk.

"So far, GM food that has been officially approved by government authorities is safe," he said.

Chinese biosafety certificates have been issued to some GM strains of cotton, rice, corn and papaya, among which only cotton and papaya are allowed to be commercially planted, according to the Ministry of Agriculture.

Meanwhile, import certificates for GM crops in China have been given to soybeans, corn, rape, cotton and beets, allowing them to be imported as raw materials for domestic processing, the ministry said.

"Government authorities really need to enhance their efforts to educate the public about GM technology since many ordinary people were confused by rumors," Huang said.

"Meanwhile, a series of measures on strengthening supervision of labeling GM products should also be strengthened to protect consumers' right to know," he said.