BANGKOK - Thai police on Wednesday said they had detained a 25-year-old man for suspected royal defamation after he allegedly posted online a forged report on the health of the country's ailing but revered monarch.
The statement, mocked-up to look like an official palace notice, began circulating online late Monday, spreading quickly through social media and messaging apps.
It claimed to give details about 87-year-old King Bhumibol Adulyadej's health, prompting Thailand's junta to issue a swift denial of its veracity and pledge to hunt down the author of the fake report.
Late on Tuesday authorities detained Krit Buddeejin, 25, a musician from northeast Thailand, without given further details.
"Police will investigate whether he was involved in making the statement or not," national police spokesman Prawut Thawornsiri told reporters on Wednesday.
"He was detained by the military under martial law and police will fast-track an arrest warrant under article 112 and the Computer Crime Act," he added.
Section 112 of Thailand's criminal code is the kingdom's controversial royal defamation law, one of the world's strictest. It carries up to 15 years in jail for each count of insulting, threatening or defaming the king, queen, heir or regent.
Both local and international media routinely self-censor when covering issues related to the royal family in Thailand.
Even repeating details of charges could break the law, making it impossible for media inside Thailand to relay the full content of the false report.
The health of King Bhumibol, who has been largely confined to hospital in recent months, is an extremely sensitive subject.
Bhumibol, the world's longest-serving sovereign, is widely seen as a unifying father figure in a nation beset with bitter political divisions, and there are profound concerns over the kingdom's future as his reign enters its twilight years.
Rights groups say 112 prosecutions have surged since the army seized power in May, as the military burnishes its reputation as the defender of the royal family.
Critics say the lese majeste law has been politicised, noting that many of those charged in recent years have been linked to the Red Shirt movement who support fugitive former premier Thaksin Shinawatra.
Thaksin's sister Yingluck was toppled as premier just before the May coup.
Police on Wednesday alleged that suspect was a local member of the United Front of Democracy Against Dictatorship (UDD) - the official name for the Red Shirt movement.
The circulation of the forged statement - which was even briefly reproduced on the website of a royalist newspaper - drew outrage from junta chief Prayut Chan-O-Cha who called on Thais not to share it further.
"We must find the perpetrators... it's not acceptable to the Thai people," Prayut, who is also prime minister, told reporters Tuesday.
Thailand has lost nearly a decade to political turmoil.
The period has been punctuated by massive, and often violent, street protests, two coups and the removal by courts of three premiers linked to the Shinawatras - whose populist parties have won every election since 2001.