Genetically modified rice seeds, along with some rice and rice products, have been on sale in Hunan and Hubei provinces, Greenpeace China claimed during a press conference on Wednesday. Local food authorities said investigations are underway.

The organization claimed three batches of tested GM rice seeds contained the genetic fragment BT, a bacterium that creates proteins to naturally repel insects.

Scientists do not yet agree that the BT gene is safe for human consumption.

The seeds were on sale in Xiantao city of Hubei province and Changde city of Hunan province, the report said.

The survey was conducted at local seed markets in eight cities in two of China's top rice-cultivating provinces during March and April.

"The GM rice seeds will very likely be sown in the coming May. Without immediate action, GM rice might further enter the country's food chain and threaten consumers' health," Wang Weikang, spokesperson of Greenpeace's food and agriculture program, said at the conference.

"Scientists hold different views on whether GM food can harm human health, but without confirmation on its safety, especially long-term, we regard it as a potential threat," Wang said.

Local food authorities started taking action last week.

The Changde agriculture bureau launched a crackdown on GM rice seeds last Wednesday, sending two batches of suspected GM rice seeds for further tests.

One batch of seeds coincided with that tested by Greenpeace.

"The samples have been sent for tests, and we're expecting the results by next Wednesday," an official from the bureau said on Wednesday.

In November, the Ministry of Agriculture granted bio-safety certificates to two pest-resistant GM rice varieties and corn.

"The certificates, based on fair safety evaluation, won't mean GM rice would immediately be commercially planted. It will require production trials and registration," Wei Chao'an, vice-agriculture minister, said at a press conference in March.

He was also quoted as saying that the country had so far approved neither commercial cultivation nor importation of GM grain.

But GM rice has already entered the country's market, Greenpeace claimed, since seven batches of GM rice and rice products in Hubei, Hunan, Fujian and Guangdong provinces were also detected during its surveys in eight provinces and the Hong Kong special administrative region from July 2009 to February this year.

The reports follow a previous series of surveys by the organization concerning GM food in the country.

In mid-March, Greenpeace said GM rice marketed under the brands of Maoya and Xueyou were detected in Wal-Mart and Zhongbai supermarkets in Hunan.

In 2005, Greenpeace leaders said the organization had found unapproved transgenic rice being illegally grown on a large scale in Hubei.