WUHAN, July 29 -- A central Chinese city has reported reduced rice sales since a supermarket was exposed selling illegal genetically modified (GM) rice.

Sales staff at several supermarkets in Wuhan, capital of Hubei, said rice sales dropped suddenly this week following a China Central Television report on Saturday that accused a local supermarket of selling rice that contained GM varieties.

"Customers keep asking whether it is GM rice," said one saleswoman at Zhongbai, a local supermarket chain.

China has not approved commercial planting or sales of GM rice and the Ministry of Agriculture on Tuesday promised zero tolerance for sales and cultivation of GM crops.

Hubei has launched an investigation following the media exposure.

Though many scientists have defended the safety of GM technology, sales remain controversial in China, with many consumers complaining of not being well enough informed.

"I'm not against GM products, but being kept in the dark. You should let consumers decide whether to eat GM products," said a shopper surnamed Wang.