“The Cabinet has already approved hemp as an economic plant,” Sirinya Sittichai, secretary-general of the Narcotics Control Board, said yesterday.

“The Thailand Tobacco Monopoly will buy the harvest from growers.”

The plantation areas are 15 districts in six provinces – Chiang Mai, Chiang Rai, Nan, Phetchabun, Mae Hong Son and Tak.

The permitted species of the herb must contain less than 1 per cent of THC.

“If the THC percentage is higher, growers will face legal punishment,” he said.

The NCB has been adjusting the legal status formerly contraband hemp, marijuana, kratom (Mitragyna speciosa) and methamphetamine.

These four substances have long seen as illicit drugs in Thailand, but authorities have decided to decriminalise them to a certain extent because they can be used in the health and other industries.

Hemp’s bast fibres can be used to make handicrafts, so locals in hemp-growing areas can earn extra income.

For kratom, authorities have conducted studies on how best to control its use.

“For example, we may treat kratom as a herb but stipulate clearly in laws that kratom can be chewed or boiled for consumption only,” Sirinya said.

“Any other form of processing will not be allowed. We won’t allow mixing kratom with other types of substances either.”

A panel led by Charnchao Chaiyanukij, permanent secretary at the Justice Ministry, was studying a new way of controlling marijuana.

“Some substances in marijuana are dangerous. But marijuana can also be used for medical purposes,” Sirinya said.

“We therefore need to study the matter thoroughly.”

Similar studies were also underway for methamphetamine, he added.