EXPERTS from the Central Science Laboratory (CSL), at Sand Hutton, near York, are investigating how unauthorised genetically modified plants got into crop trials.

On two GM sugar beet trial sites, one in Cambridgeshire and one in Oxfordshire, an unauthorised GM beet line was found, though no threat was posed to human health or the environment.

The statutory inspection and enforcement team at the CSL has submitted a preliminary report to Government ministers.

But they are continuing to investigate and consider further action, including the possibility of prosecution.

GM seed company Aventis informed the Government of the situation after discovering a background level of a second, unauthorised, herbicide-tolerant GM beet line as part of the routine destruction of crops.

The company used this batch of GM seed at ten small trial sites in England this spring, though they are not part of the farm scale evaluations.

Two of the sites showed evidence of the unauthorised seed, though the trials are now finished and the sites have been cleared of all GM plant material.