U.S.-based The Rice Trader, organizer of the annual contest that started in 2009, said only the ST25 rice variants produced by the company of Ho Quang Tri, the son of the main developer of the rice, Ho Quang Cua, is allowed to use the "World’s Best Rice" title in promoting this product.

However, many Vietnamese companies have been printing this title on their product packages without permission from The Rice Trader, which is a copyright infringement, it said in a statement.

Should these actions persist, the organization will release the names of the infringers and take away Vietnam’s rights to participate in the contest in upcoming years, it warned.

The ST25 variety from Vietnam won the World’s Best Rice Contest in 2019 and secured the second place last year, losing the first place to a jasmine fragrance variety from Thailand.

The ST25 variety is the result of 25 years of work by Cua and his colleagues who cross-bred the premium fragrant rice, described as having a sweet taste and a hint of pineapple flavor, in the Mekong Delta province of Soc Trang.

Other countries that have won the contest in previous years include Thailand, the U.S. and Cambodia.