Thailand is set to become the first Asian country to legalize medical marijuana, but a battle is brewing between local and foreign firms over control of a potentially lucrative market.

With parliament set to approve the legislation as early as next month, Thai businesses and activists have raised concerns that a raft of patent requests filed by foreign firms could allow them to dominate the market and make it harder for researchers to access marijuana extracts.

“Granting these patents is scary because it blocks innovation and stops other businesses and researchers from doing anything related with cannabis,” said Chokwan Kitty Chopaka, an activist with Highlands Network, a cannabis legalization advocacy group in Thailand.

“We were very shocked to see this because it would be like allowing them to patent water and its uses,” Chokwan said, adding that applicants are seeking patents for plant-related substances, which are not allowed under Thai law.

Opposition to foreign firms has threatened to stall the legalization process, with researchers and civic networks threatening to sue the government if the patents are granted, according to media. [Read more at Reuters]