Defra told Grower that it is reviewing the issue because "we are concerned that legitimate research and development should not be hampered by people taking the law into their own hands".
It does not yet have specific plans but its review could be stepped up any moment as BASF starts its trial of a blight-resistant potato at the National Institute of Agricultural Botany (NIAB) in Cambridgeshire.
A Defra representative said: "If the Government was to decide in due course that something should be done to reduce the risk of vandalism, all possible options would be considered."
BASF attempted to undertake an identical trial last year but the plants were ripped up in an overnight raid by anti-GM campaigners.
The firm's plans to trial the variety at an approved site in Drayton, Derbyshire, were also scrapped last year because of the farmer's concerns for his personal security (Grower, 9 March 2007).
As a result of these actions, the Agricultural Biotechnology Council (ABC) is calling for the location of all trial sites to be kept under wraps. Currently, multinationals like BASF must publish a six-figure grid reference that clearly identifies the location of the field.
ABC chairman Julian Little told Grower: "Most countries do not release the sort of specific information on crop trials that has to be given in Britain. The obligation to publicise the specific location of a GM crop is contained in a European Directive but is interpreted differently across the member states. We in the UK must clarify the framework under which trials may be carried out undisturbed by vandalism."
A Defra representative said it would consider the possibility of keeping trials secret but added that it would be tricky: "EU law requires GM trial locations to be disclosed to the public in some form, so the idea of making it harder to identify trial sites would not necessarily be a straightforward option."
BASF representative Chris Wilson told Grower that it is considering security options for its trial.
Statistics last month revealed that global cultivation of GM crops increased by 12 per cent last year.