Former communist insurgent Surachai Danwattananusorn and his “aides” Phoochana and Kasalong (surnames not known) were apparently living in self-imposed exile in Laos when they went missing in December.
The aides were separately found dead on December 26 and 27, in the Mekong River that forms the border between the countries.
Their hands and feet were bound, their faces beaten to such an extent that facial recognition was impossible, and their abdominal organs had been replaced with concrete to weigh the bodies down.
Thai forensic examiners confirmed on Tuesday that DNA from the bodies matched that of Phoochana and Kasalong.
Surachai, a prominent anti-monarchist, and his aides were last seen alive in Vientiane on December 11. Their colleagues promptly reported their disappearance to Lao authorities.
The identification of the aides’ bodies raised grave concerns for Surachai’s fate, Human Rights Watch said in a statement.