Min Khin, a senior minister and one of the earliest advocates for an international tribunal to prosecute crimes committed during the Khmer Rouge regime, died on Friday morning at the age of 78.

Khin’s eldest son, Min Madeth, said on Thursday that treatment his father had been receiving in Thailand in recent months had ceased to be effective and the family were to transport him back to Phnom Penh to deliver his last words to his loved ones that night.

Government spokesperson Phay Siphan said yesterday that Khin was on the verge of death for the journey and stopped breathing when oxygen delivery equipment was removed upon his arrival on Friday morning.

Khin was minister of cults and religion from 2008 until this March, when he was appointed minister of special missions in a reshuffle.

With the exception of the Khmer Rouge regime, Khin spent the majority of his adult life in public service. Prior to the evacuation of Phnom Penh, he had been a clerk at the city’s municipal court. It was this legal apprenticeship that would provide him with the tools to set about in 1979 becoming, in the words of director of the Documentation Centre of Cambodia (DC-Cam) Youk Chhang, “the first Cambodian genocide researcher in Cambodia”.

Khin was employed by the Vietnamese-led government in 1979 to travel the country collecting survivor testimony “with empty hands [and] only a piece of paper and a pencil to document the Khmer Rouge crimes”, Chhang said. In 1983, Khin published his report and, along with it, a petition bearing the signatures and thumbprints of 1.1 million survivors. The petition called for an international tribunal to investigate and try the crimes of the Khmer Rouge.

Khin had said that lack of international recognition for the People’s Republic of Kampuchea left the petition with nowhere to be delivered, and when Vietnamese forces withdrew in 1989, the boxes containing his research were almost cast into the Mekong River along with thousands of other official documents.

The boxes, however, were saved and provided Chhang with the foundations to begin his work at DC-Cam, following up with as many of the signatories as he could, eventually leading to thousands of civil party suits at the Extraordinary Chambers in the Courts of Cambodia. “He actually captured the history of the crimes in a way nobody else can do it,” Chhang said.

Khin is survived by six children.