Former Khmer Rouge foreign minister Ieng Sary (centre) claps during an inspection of railway tracks in Takeo province in 1977. Photograph: Dc-cam

Khmer Rouge tribunal defendant Ieng Sary, who served as deputy prime minister of foreign affairs for a regime that oversaw the deaths of nearly two million people, died yesterday at the age of 87 from heart failure.

The trial of Sary, along with two other top Khmer Rouge leaders, remained ongoing when he died. His wife, Ieng Thirith – Khmer Rouge minister of social affairs – was a co-defendant in the same case until she was declared unfit to stand trial last year due to dementia.

As the oldest living leaders of the regime, Sary and Thirith, along with Brother No. 2 Nuon Chea and head of state Khieu Samphan, were being tried for a raft of crimes against humanity charges. The case will continue, though the charges against Sary were extinguished upon his death.

Born October 24, 1925, in what is present-day southern Vietnam, Sary was the son of a Chinese immigrant mother and a father who belonged to the Khmer Krom minority – one of the groups that would eventually be singled out for persecution under the Khmer Rouge’s Democratic Kampuchea regime.

According to court documents, Sary enrolled in secondary school at Sisowath High School in the 1940s, where he met Khieu Thirith, his future wife and co-defendant for her role as the Khmer Rouge’s chief propagandist. While there, Sary also met Saloth Sar – a man who would become better known as Pol Pot, Brother No. 1 and architect of the Khmer Rouge’s ultra-Maoist revolution.

In 1950, Sary won a scholarship to study at the Instituts études politiques de Paris and moved to France, where he began to dabble in communism, ultimately becoming a founding member of the Marxist Circle of Khmer Students.

Like several other intellectual leaders of the Khmer Rouge, Sary became a teacher upon returning to Cambodia in 1957, holding a professorship in history and geography at the Kampucheabot Private High School

But in 1963, his life in academia ended when he was singled out as a “leftist” by then-King Norodom Sihanouk and fled to the Vietnamese border to join Pol Pot.  

In the same year, Sary became a full-rights member of the standing committee of the Workers Party of Kampuchea.

Presaging his future role as foreign minister, Sary travelled to Hanoi in 1970 to establish the radio station “Voice of the FUNK” or National United Front of Kampuchea.

He then flew on to China, where he became “Special Envoy of the Internal Resistance in Beijing”, liaising with both deposed King Sihanouk and the Chinese Communist Party, which would become the Khmer Rouge’s greatest patron.

Sary was announced as the Khmer Rouge’s foreign minister in August 1975, just four months after the group finally wrested the last vestiges of control from the US-backed Lon Nol regime and emptied Cambodia’s cities on April 17.

Sary himself, however, has since disputed the date, saying he didn’t assume the role until the following year.

During his tenure as foreign minister, Sary was instrumental in overseeing the return of Cambodian intellectuals living abroad to Democratic Kampuchea. Most of these returnees were interned for re-education – as was current Foreign Minister Hor Namhong. Of those returnees, several were arrested, tortured and murdered at S-21.

According to the indictment in Case 002, Ieng Sary reportedly said in 1996 that he was “very regretful for the deaths of the intellectuals, because I was the one who gathered them to come to help build the country”.

Others, however, contest this statement of contrition, as did Philip Short, author of Pol Pot: Anatomy of a Nightmare.

“Nghet Chhopininto, who was in charge of arrangements in Paris for Cambodian students in France to return to [Democratic Kampuchea], worked directly to Ieng Sary,” Short said in an email yesterday. “Before he died, Chhopininto accused Sary of tricking those who returned. Sary had known what they were coming back to. He had marked some of them as ‘unreliable’ which meant they faced almost certain death. Yet still he brought them back.”

“About 10 years ago, Chhopininto returned to Cambodia and spent several days with Sary,” he continued. “He told me that, even in their private conversations, Sary continued to praise the achievements of the Khmer Rouge. There was no word of regret.”

As part of his job, Sary travelled extensively, becoming the face of Democratic Kampuchea abroad on state visits and in meetings at the UN. He would later argue that he had been away frequently and had no hand in the regime’s atrocities.

Short allowed that Sary was not one of the chief authors of the Khmer Rouge experiment – which he described as “an abomination” – but maintained that the ex-minister still bore responsibility for the regime’s crimes.

“Last week [speaking to a gathering of journalists] I was merely trying to say that the leadership’s ideas were utopian – Pol Pot, above all, and men like Khieu Samphan and no doubt Nuon Chea – genuinely wanted to better the lot of the poorest Cambodians, but the methods they used turned the country into hell on earth,” he said. “It’s a very extreme example of the old saw, ‘the road to hell is paved with good intentions’. Ieng Sary was not one of those who mapped out the utopian vision. But he did have a major role in putting it into practice with all the appalling consequences that followed.”

Sary was also the face of Democratic Kampuchea at home, where he would escort foreign delegations who visited the fledgling “agrarian utopia”.

On one such visit, just before the regime’s fall, British professor and self-proclaimed Khmer Rouge sympathiser Malcolm Caldwell was shot and killed. Caldwell had been joined on the trip by American journalists Richard Dudman and Elizabeth Becker.

In confessions tortured out of them, Caldwell’s killers said they had been hired to assassinate him to shame the regime, and perhaps to shame Sary personally. However, in her book When the War Was Over, Becker maintained that “Malcolm Caldwell’s death was caused by the madness of the regime he openly admired”.

“No, I haven’t changed my mind since writing my book,” she said in an email last year.  “However, what was striking was how long it took for anyone to come to our rescue. There was no doubt that our visit was sponsored by the Ministry of Foreign Affairs.”

Caldwell’s killers’ confessions were extracted at the infamous S-21 detention centre, a crime site that the court is now considering adding to the case against Sary’s two remaining co-defendants.

As the Khmer Rouge’s monopoly on power collapsed on January 7, 1979, Sary fled with his comrades, who continued to lead a resistance movement against the new, Vietnamese-backed government.

He defected in 1996 and received a royal pardon, a fact cited by his defence following his 2007 arrest as evidence of his ineligibility to stand trial at the ECCC.

Sary’s experience at the ECCC was bookended by silence and absence.

In 2011, as the trials were beginning, Sary took the stand to give a brief statement, only to reiterate his previously expressed intention to exercise his right to remain silent.

Those who knew and had dealt with Sary offered varying estimations of his character.

“By dint of his job, Ieng Sary was expected to be open to foreigners,” said Elizabeth Becker, who interviewed Sary multiple times. “He wasn’t professionally friendly, but he was approachable.”

Defence lawyer Michael Karnavas, on the other hand, described Sary as “friendly, open [and] engaging”.

“One hears a lot about his personality, but how much time did they really spend with him?” he asked in an email. “I think it is easy to conjure up images when you have preconceived opinions, do not fully appreciate the culture, are working through translators and relying on impressions formed by others who may have reasons to embellish or even lie. Mr Ieng Sary always greeted me with a smile, was polite even when I pressed him with difficult questions, and to the very end, never failed to express his gratitude on each and every occasion I met him.”

However, Philip Short – who interviewed Sary several times over lunch in 2000 and 2001, and called the former revolutionary “a gourmet” – had somewhat harsher words.

“The impression I had from talking to those who worked for him at B1 (the [Khmer Rouge] Foreign Ministry) was that he was feared and mistrusted, insisting (as he did when he was a student in the Marxist Circle in Paris) that all around him must show a degree of self-denial and revolutionary correctness which he never applied to himself,” he said. “There were exceptions – men he took under his wing and who were loyal to him in return. But to most of his associates, he was as slippery as an eel.”

Regardless of how the world will remember him, in parts of Cambodia where the Khmer Rouge still has stout supporters, Ieng Sary is likely to be remembered as he is by his former employee, 51-year-old Khim Kheng, councillor of Malai commune in Banteay Meanchey.

“I worked for the Khmer Rouge since I was 18 as a cook for the international guests who came to meet with the leaders of the Khmer Rouge,” said Kheng, who described Sary as “pleasant and modest”.

“When the Khmer Rouge was toppled, I joined with Ieng Sary and the other leaders in the jungle and worked in the transportation unit until the Khmer Rouge forces integrated with the government in 1996. I regret his death, but I think it is good, because he can avoid jail and his sorrow is over. I will of course join his funeral when the ceremony is celebrated in Malai.”

ADDITIONAL REPORTING BY JOE FREEMAN, SOKHA CHEANG AND DANSON CHEONG