A biodiversity protection network has opposed a kratom patent being registered by a Japanese research team, saying it violates biodiversity laws.
BioThai Foundation director Witoon Lianchamroon said a petition will be filed this week with the Commerce Ministry asking the Department of Intellectual Property to take action against the patent.
He said the patent was contrary to the Convention on Biological Diversity which has been ratified by the two countries. Kratom is part of the country's biodiversity and a traditional medicine.
He said kratom has been used to "stimulate freshness and kill pain since ancient times". But the Japanese researchers laid claim to the plant's benefits through a Thai-Japanese research project and patented it.
"Japan is obviously going against the convention, which clearly states that benefit sharing must include the country that owns the property," Mr Witoon said.
"The department must do its job to protect the country's interests by amending intellectual property laws to boost our right to share in the benefits."
He said the department must not repeat its failure with the herb kwao krua (Pueraria mirifica). Japan was granted a patent on the plant 12 years ago, preventing Thailand from using it to develop products.
In 2014, the Japanese researchers gained a patent on kratom's mitragynine substance which reduces pain and has fewer side effects than opium and marijuana.
Jiraporn Limpananont of Chulalongkorn University's Social Pharmacy Research Unit said the discovery of mitragynine involved no "inventive steps", a condition for a patent.