A Canadian farmer who opposes genetically modified crops has warned farmers to stay away from GM seeds, saying their rights could be threatened by biotechnology giants such as Monsanto.

I want to tell Thai farmers not to let them (GM seeds) enter your country. Once you grow them on your land, there's no turning back because the seeds will spread everywhere. Every organic farm in Thailand will be contaminated with GMO, which could spread by wind,'' said Percy Schmeiser, a farmer growing canola, a type of oilseed rape. He was speaking at a Greenpeace Southeast Asia briefing.

Mr Schmeiser attracted international attention when Monsanto, a company selling agro-chemicals and biotechnology, took him to court in 1998, claiming he planted the firm's genetically engineered canola seeds without paying for them.

Mr Schmeiser said Monsanto's seeds were growing on his land, but he did not plant them. Grain trucks or wind had spread them to his fields.

The Federal Court of Canada found Mr Schmeiser guilty last year. The judge told me that no matter how the seeds came to be there, if the firm's GM canola existed on my field, I would have to pay Monsanto,'' said Mr Schmeiser, who has appealed against the verdict.

He urged farmers to protect their land from GMO by using only native seeds developed by ancestors.

Don't ever buy seeds from a multi-national company like Monsanto. Farmers in Canada have found out that the seeds produce less yield than the indigenous ones.

Monsanto's GM seeds can also turn you into a slave on your own land because the company will commit you to buy its seeds, pesticides and fertilisers,'' he said, adding that after harvesting, GM plants could become pesticide-resistant. Sunya Bhummichit, crops science director for Monsanto Thailand, said a case such as Mr Schmeiser's could not happen here.

Thai farmers were protected under the Plant Variety Protection Act, which gave them the right to keep and develop seeds for the next growing season. A government ban on GMO also prevented Monsanto from distributing GM seeds here.

Only research in laboratories and greenhouses is allowed at present.

Banpot said field research was very important to the whole research scheme.

Without field experiments, research on GM crops cannot be completed and we cannot judge whether any crop should be commercially grown or not, he said.

He added that while waiting for the biosafety legislation, as the assembly had requested, the countrys biotechnology would lag behind because it would take time to draw up the law.