Dated May 2, the letter was sent by Ambassador Sarun Charoensuwan to Cha Myung-seok of the May 18 Memorial Foundation.

A copy of the letter was circulating on social media on Monday.

There was speculation that the letter was written in response to a note from the foundation’s director sent recently to Thai officials including Prime Minister Prayut Chan-o-cha and the Thai Ambassador to Seoul. The letter asked that Jatupat be freed so he could attend the ceremony and receive the award.

Jatupat was given the foundation’s Gwangju Prize for human rights.

In the letter, the ambassador said the activist had violated lese majeste and computer crime laws and had his bail revoked in December. The ambassador said Jatupat was receiving a fair trial.

He said Thailand gave importance to freedom of expression, but within reason to maintain order.

An informed source in the Ministry of Foreign Affairs confirmed the letter from the Ambassador was authentic.

On Monday, the Khon Kaen Court objected to Jatupat’s latest bid to get bail so he will not be able to collect the prize at a ceremony in South Korea next week.

He won the award for his “courage in fighting against a non-democratic regime”, according to the foundation.

Jatupat has been in jail for almost six months already after sharing a BBC report on Facebook deemed to have insulted the monarchy.