PHNOM PENH -- Six months ago, Thai political activist Wanchalearm Satsaksit was snatched from outside his condominium building in Phnom Penh and bundled into an SUV by three armed men.
More than 500 km away at his family home in northern Thailand, Wanchalearm's sister Sitanan Satsaksit heard the late afternoon abduction take place as it unfolded during a regular call with her younger brother.
She is the last relative to have heard his voice.
"The last words he said in our phone call was that he was buying meatballs," Sitanan told Nikkei Asia. "Then I heard a noise that sounded like a car accident. I heard the sound of people talking, not in Thai, I think it was Cambodian. Then I heard Wanchalearm say 'I cannot breathe, I cannot breathe.'"
Wanchalearm, who fled to Cambodia after Thailand's military seized power in a May 2014 coup, is not the only Thai dissident to disappear in suspicious circumstances, some of whom have turned up dead. And even though the country has ostensibly returned to a civilian government, it is still run by the former army general who led the takeover six years ago. Sitanan and others can't help but see a link between the missing and their opposition to authoritarian rule.
Seeking answers, Sitanan has traveled to Cambodia.
Last week, to mark the six-month anniversary of her brother's June 4 abduction, she visited the site where the 37-year-old was taken and participated in a Buddhist prayer ceremony.
On Tuesday, she appeared as a witness in a Cambodian court hearing that will decide how the case will proceed.
"I hope to get justice and find the truth," said Sitanan, who has hired a Cambodian lawyer to push for a full investigation.
"The Cambodian authorities have demonstrated negligible progress in the investigation, despite important pieces of evidence coming to public light in the intervening months," Amnesty International said in a report published on Tuesday. "To this day, Wanchalearm's fate and whereabouts remain unknown."
After fleeing to Cambodia, Wanchalearm, affiliated with Thailand's pro-democracy "red shirt" movement, had remained politically active online. That prompted Thai authorities in 2018 to issue a warrant for his arrest for allegedly violating Thailand's Computer-Related Crime Act.
Sitanan said in recent years that police and military officers would irregularly visit their family home in the northeastern city of Ubon Ratchathani to ask about her brother.
She said Wanchalearm would also send her photos of people he suspected were following him in Cambodia, pictures she intends to submit as evidence to the court. She said that signs point to the involvement of the Thai state.
"He was quite vocal in criticizing the government, but I don't know what level of his criticism triggered the perpetrators," she said.
"He is not going to the casino, he is not dealing in drugs, he is not an enemy to anybody that we know, so there is only one obvious or outstanding activity for him, [it] is politics," she said. "There was no ransom, no one wanted money."
Phil Robertson, deputy Asia director at Human Rights Watch, said eight more Thai political exiles had gone missing, including two whose bodies were found by the Mekong river in northern Thailand.
"All of them were at various times under supervision and protection of Lao or Cambodian authorities, so it is clear the danger came from across the border in Thailand," said Robertson.
"The Thai government has made a number of unsatisfactory denials about their involvement and the fate of these nine political activists," Robertson said. "Many observers correctly point to the fact that the past 5 years have seen numerous, highly suspicious 'swap mart' style deals for refugees and exiles between Thailand and its neighbors that started under the military NCPO government," Robertson added, referring to the National Council for Peace and Order that ruled Thailand from 2014 until last year.
"Most obvious was the forced return of 109 Uighurs to China, but there have been other cases that have seen refugees sent back into harm's way in Laos, Cambodia, Vietnam, and other rights repressing countries," he said. The Uighurs are a mostly Muslim ethnic group largely inhabiting the western region of Xinjiang and who human rights groups, Western governments and the United Nations say China persecutes.
The Thai embassy in June requested the Cambodian government to verify whether Wanchalearm had disappeared. The same month, Thai Foreign Minister Don Pramudwinai said Thailand had to wait for Cambodia to finish its investigation because he did not have political refugee status, the Bangkok Post reported.
Despite Sitanan's push for justice, the prospect of Cambodia's corrupt and politically-controlled judiciary delivering any insight into Wanchalearm's fate remains highly remote.
Reluctant to start a probe, some Cambodian officials even questioned whether the activist was in the country at all -- assertions Sitanan says she can easily refute with pictures and videos.
Following pressure by the U.N., the Phnom Penh court launched a case of "unlawful arrest, detention and confinement, and unauthorized possession of weapons" against "unidentified individuals."
Court spokesman Y Rin on Tuesday said he could not discuss details of the probe as it was ongoing.
"This is the investigation stage, the investigative judge is completing the judicial investigative process, in accordance with the law, so we cannot reveal the information," he told Nikkei.
Sitanan says she will continue to fight to find out what happened to her brother, a long time activist for social and political rights who worked for years at NGOs helping marginalized groups.
She has met with families of other disappeared Thai activists and says she is inspired by the "fearless" youth protesters now facing off with the government back at home and defying harsh laws that prohibit criticism of the monarchy to speak out.
"I want to stand company, [to make sure] that there will be no more enforced disappearances," she said. "Whoever is the perpetrator of this crime, you had no right. Whoever you are, you have no right to do this to anyone."