A rights group says three Thai citizens who were accused of insulting the king have disappeared.
Thai Alliance for Human Rights claims there’s no sign of the trio after they were arrested in Vietnam.
However Prawit Wongsuwan, Thailand’s deputy prime minister, denies the activists were in Thai custody.
The incident comes months after two exiled critics of the monarchy were found dead.
Last week Thailand crowned its new king, Maha Vajiralongkorn, in an elaborate ceremony at the Grand Palace in Bangkok.

Kuwait suspends flights, activates emergency plan after Iranian attack on airport
Fire in Delhi hotel kills at least 21, police say
US to re-engage with Gavi vaccine alliance amid Ebola outbreak
Israeli fire kills four people in Gaza, medics say
Philippines' Marcos urges Senate to return to work as gridlock deepens ahead of break
