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.

Jordan intercepts 18 Iranian ballistic missiles
US hits five Iranian oil tankers after attack on Navy ships
Air traffic control issue disrupts flights at major UK airports
At least 73 injured after Houthi rebels attack Saudi civilian and energy facilities
UK, France and Canada sanction Israeli West Bank settlements
