Three Thai activists facing charges of insulting the monarchy have disappeared after reportedly being arrested in Vietnam, months after two exiled critics of the military and monarchy died.

The three dissidents had fled lese-majesty charges and continued to broadcast anti-monarchist and anti-junta commentary from exile. Chucheep Chiwasut – known as Uncle Sanam Luang – Siam Theerawut and Kritsana Thapthai were reportedly stopped after crossing over the border from Laosinto Vietnam a month ago, reportedly using fake passports.

According to Human Rights Watch, Vietnam handed the dissidents over to Thai authorities on 8 May, but they have not been seen since, and there has been no acknowledgement of their arrest and detention. Thailand’s deputy prime minister, Prawit Wongsuwan, denied the activists were in Thai custody.

Brad Adams, the executive director of Human Rights Watch Asia, said: “Vietnam’s alleged secret forced return to Thailand of three prominent activists should set off alarm bells in the international community.”

Article 112 of Thailand’s criminal code says anyone who insults the king, queen, heir or regent faces punishment of up to 15 years in prison.

Following a military coup in the country in 2014, many activists who were part of the pro-democracy “red shirt” movement and had voiced anti-monarchist sentiment were forced to flee to Laos, where dozens have been hiding out since.

Many, including Chucheep, continued their anti-monarchist activism from exile, broadcasting messages through radio and YouTube channels that were considered incendiary to the military junta and the monarchy.

In March, it was confirmed to the Guardian by another lese-majesty exile, Yammy Faiyen, who had stayed briefly with Chucheep in hiding, that Chucheep’s name was at the top of an unofficial warrant of exiles living in Laos that the Thai government wanted to track down.

“Uncle Sanam Luang is the one who Thai government wants the most,” said Yammy.

Since 2016, a number of activists have either been found dead or mysteriously disappeared, raising questions about their safety in Laos and the role of Thailand’s military government in the disappearances. The junta has consistently denied any culpability.

In June 2016, Ittipon Sukpaen, known as DJ Sunho, disappeared without trace. He had been charged with violation of lese-majesty laws in Thailand and was hiding in the outskirts of the Laos capital, Vientiane, where he continued to broadcast anti-monarchy YouTube videos.

In 2017, the wife of an exiled host of an anti-monarchist radio show witnessed his abduction from their house in Vientiane. Wuthipong Kachathamakul, known as Ko Tee, has not been seen since.

Then in December last year, one of Thailand’s best-known dissidents, Surachai Danwattananusorn, and two other exiles with whom he was living in Laos, Chatcharn Buppawan and Kraidej Luelert, disappeared from their home.

Two weeks later, the bodies of Chatcharn and Kraidej washed up on the banks of the Mekong River on the Thai side. They had been disembowelled and stuffed with concrete, their legs broken and their hands handcuffed, as well as tied with rope at the neck, waist and knees. Surachai’s body has not been found.

It is believed Chucheep was attempting to cross into Vietnam because he and the other exiles feared for their safety in Laos.

The US-based Thai Alliance for Human Rights was the first to report that Chucheep and his fellow exiles had been turned over to Thailand. “We are worried about the situation,” said Piangdin Rakthai, a spokesman for the campaign group. “There have been disappearances and deaths of political activists who are against the military government and criticise the monarchy.”

Separately on Friday, a former law student was released from jail a month before the end of his two-and-a-half-year sentence for a 2017 lese-majesty conviction.

Jatupat Boonpattaraksa, an activist and critic of the ruling junta, was jailed for posting a profile of King Maha Vajiralongkorn published by the BBC’s Thailanguage service that was deemed offensive. His release was part of a royal amnesty for thousands of prisoners to mark the king’s coronation this week.

Hannah Ellis-Petersen

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