Koh Tang, an idyllic maritime outpost about 50 km off Cambodia’s southern coast, is best known as the site of the May 1975 Mayaguez incident, when Khmer Rouge forces captured a U.S. container ship and 41 American servicemen died in a rescue attempt.
But the attention of researchers at the Documentation Center of Cambodia (DC-Cam) has been sharply focused on the island since January, when a Vietnamese military official claimed it had been the site of a large-scale massacre of Vietnamese citizens at the hands of Khmer Rouge captors.
An article published in Vietnam’s Tuoi Tre News in January quotes a Vietnamese colonel, Bui Van Bong, who “recalled seeing the gruesome evidence of killings when he set foot on Koh Tang” several years after the capture of about 600 Vietnamese from the island of Tho Chu in May 1975. The article says 513 of these captured people from Tho Chu were taken to Koh Tang by the Khmer Rouge.
An islander is also quoted as saying that bound bodies were found at the feet of coconut trees, planted using forced labor. Some of the victims had been tied to a tree and put to death.
DC-Cam’s executive director, Youk Chhang, said he has been investigating the issue of the 600 missing Vietnamese since 1998. In 2000, Mr. Chhang interviewed a high-ranking Vietnamese official, Nguyen Gia Dang, about the issue.
“[Mr. Dang] said the Khmer Rouge captured at least 600 Vietnamese civilians from Tho Chu island and occupied the island as well. The Khmer Rouge later shipped those 600 Vietnamese civilians to Cambodia mainland,” Mr. Chhang said in an email.
But when the Vietnamese attacked and reclaimed their island later in 1975, they took the Khmer Rouge soldiers there hostage, releasing them only on the promise that the 600 Vietnamese would be returned.
Instead, a commander told them that “all are dead,” and Mr. Dang said that Nuon Chea, the Khmer Rouge second-in-command, later told him, “Ta Mok killed them all.”
DC-Cam investigator Long Dany has been connecting the dots on this new information since January—evidenced by a piece of paper he has covered in black-ink diagrams, tidbits of information and arrows pointing in all directions, charting out the facts as he goes. His investigation will likely see him revisiting old research in addition to searching for new leads.
“I have interviewed several Khmer Rouge Navy [veterans] over the past 10 years,” he said. “They have never talked about it. But if we know the information, we can ask what happened there and make a chain of command to the leaders in Phnom Penh.”
He explained that after the Khmer Rouge came to power in April 1975, the army’s Division 3 was dispatched to the Southwest Zone. So too was a regiment from the Eastern Zone which, when merged with the division, became known as Division 164.
Division 164 included the Khmer Rouge navy, and was led by a cadre called Meas Muth, who is now under investigation for crimes against humanity and war crimes at the Khmer Rouge tribunal.
The division was composed of three regiments—61, 62 and 63—and later joined by Regiment 140.
“Regiment 140 controlled the attack ships. When I interviewed soldiers, they told me Regiment 62 was sent to control Koh Tang and there were four battalions there,” Mr. Dany said, adding that the island was under the command of a man known by the revolutionary alias of Yeang, who died in 1979.
“I have met Regiment 62 people before. I will follow this case, interview them again, and ask about this new information,” Mr. Dany said.
He said the facts he gathers about the possible massacre on Koh Tang could be relevant to the Khmer Rouge tribunal’s case against Meas Muth, known as Case 003. The Cambodian government has publicly stated its opposition to the case and insisted that it must not move forward.
“This information is very important, particularly for investigating the case of Meas Muth in Case 003. We will go to the island and search for the crime sites and meet people who have lived there since the early ’80s,” Mr. Dany said.
The initial allegations compiled by prosecutors against Meas Muth do not mention a massacre on the island. The allegations were forwarded to investigating judges in 2009, and an investigation is ongoing.
Although what happened on Koh Tang might never be the subject of a court trial, finding out more about the events leading up to the alleged massacre could still have an impact on court proceedings.
William Smith, the tribunal’s deputy co-prosecutor, said in an email that the allegations could help prove there was armed conflict between Cambodia and Vietnam in 1975. This could help prosecutors demonstrate that Nuon Chea and Khieu Samphan are guilty of war crimes when proceedings in the second phase of their trial begin later this year.
Mr. Smith said the investigation into what happened on Koh Tang would also help provide “relevant context to the acts of genocide alleged to have been committed by both Accused against the Vietnamese population from 1977 onwards.” These allegations of genocide will also be heard in the next trial phase.
Vong Dara, deputy chief of Koh Tang island’s Peam Prasap village, moved to the island in 1988. He said he has always heard rumors that “the Khmer Rouge took the Vietnamese to do hard work and then smashed them.”
“Actually, there’s a rumor about this, but there is no concrete evidence to prove it,” he said by telephone.
“I mean, villagers started moving back onto and inhabiting the island again in 1985…but we didn’t see any evidence such as bones and skulls or bodies of any dead persons found in this island at all,” Mr. Dara said. “So it’s just a rumor.”
However, his colleague, 58-year-old second deputy commune chief Lang Mann, said that he once happened upon three pits containing about 100 bodies on the nearby island of Koh Chas.
“I have never heard about the killing of people, especially Vietnamese people, on Koh Tang at all,” he said. “For myself, I was digging and found about 100 bodies inside a local pagoda, Wat Sakoram, on Koh Chas,” he added.
(Additional reporting by Kuch Naren)