Thais accused of insulting King 'arrested in Vietnam'

Three activists facing charges of insulting the monarchy have disappeared after reportedly being arrested in Vietnam, rights groups said on Friday, months after two exiled critics of the military and monarchy turned up dead.

Deputy prime minister Gen Prawit Wongsuwon denied the three activists were in Thai custody, as has been reported by the Thai Alliance for Human Rights.

Chucheep Chiwasut, who broadcasts political commentary to Thailand from exile, and fellow activists Siam Theerawut and Kritsana Thapthai were reportedly turned over to Thai authorities by Vietnam on Wednesday, Human Rights Watch said in a statement.

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

London-based Amnesty International said Mr Chucheep had long faced charges of lese majeste, or insulting the monarchy.

Mr Siam and Mr Kritsana were also under police investigation for lese majeste, the rights group said.

Section 112 of the Criminal Code says anyone who insults the king, queen, heir or regent faces punishment of up to 15 years in prison.

The US-based Thai Alliance for Human Rights first reported that Mr Chucheep, also known as Uncle Sanam Luang, had been sent back to Thailand.

"Uncle Sanam Luang and two others were apprehended ... a month ago. But they were just transferred to Thailand on May 8 from Vietnam," the alliance's Piangdin Rakthai said in a YouTube video.

Gen Prawit denied the report. "Vietnam has not coordinated transfers. We have not received any request. If there is, it would be through the foreign ministry and police," he told reporters.

Human rights groups have accused the ruling military of applying the lese majeste law more widely since a 2014 military coup as a way to silence critics.

In January, the bodies of two exiled critics of the military and royal family, Chatcharn Buppawan, 56, and Kraidej Luelert, 46, were found along the Mekong River border with Laos.

Their bodies had been stuffed with concrete, apparently to make them sink.

Activist Surachai Danwattananusorn, 78, who operated an online radio station critical of the junta and monarchy from Laos, disappeared in December.

"We are worried about the situation," Mr Piangdin said in his video.

"There have been disappearances and deaths of political activists who are against the military government and criticise the monarchy."