Scientists in the US have warned that seeds from crops genetically modified for industrial or pharmaceutical use could contaminate the food chain due to inadequate regulation by US authorities.

According to a study by the Washington-based Union of Concerned Scientists, conventional corn, rape and soybean seeds showed a low level of GM contamination, which was unlikely to present a danger to human health or the environment, reported the Financial Times.

However, the UCS warned that the risk to health could increase in the future due to insufficient controls to separate GM seeds from non-GM varieties.

"This study shatters the presumption that at least one portion of the seed supply - that for traditional varieties of crops - is truly free of genetically engineered elements. The (US) government should immediately follow up this study to determine the extent of the contamination and the steps needed to protect this treasure," Margaret Mellon, director of the UCS food and environment programme, was quoted by the Financial Times as saying.

The UCS report said that pharmaceutical and industrial crops currently receive special attention due to the GM products made by such plants, but warned that "seed contamination is the back door to the food supply".