Hun Sen, whose Cambodian People’s Party took every seat in the national assembly in last month’s elections, is the world’s longest-serving prime minister (since 1985). His recent electoral victory was assured in November 2017, when Cambodia’s Supreme Court dissolved the main opposition party after the government filed a lawsuit accusing it of conspiring with foreign powers to stage a revolution. Forty years ago Hun Sen was a Khmer Rouge battalion commander. Fearing a purge, he fled to Vietnam in 1977; he returned in 1979 with Cambodian rebel forces and the Vietnamese Army which overthrew Pol Pot’s regime. The Extraordinary Chambers in the Courts of Cambodia was set up in 1997 to try ‘the most senior’ surviving Khmer Rouge leaders, or those ‘who were most responsible’ for the atrocities committed under Pol Pot.

Khem Sophath was 15 when he disappeared. He was last seen by a friend bleeding from what appeared to be a gunshot wound to the chest. His friend, who was shot in the arm, was forced to leave Sophath and run for cover as Cambodian security forces fired into a crowd of striking garment workers in Phnom Penh on 3 January.

In Cambodia there is no right to freedom of assembly. On 4 January, the interior ministry issued a statement banning all demonstrations and marches. It isn’t clear what counts as a march. Rumours spread that any gathering of more than ten people in Phnom Penh would be broken up and the participants arrested. The ban came after weeks of strikes and protests by garment workers calling for higher wages and improved working conditions. At the moment they earn around £2 a day.

On 19 July, Sam Rainsy, the self-exiled leader of the opposition Cambodian National Rescue Party, returned to Phnom Penh to much fanfare. Crowds lined the roads across the city to welcome him back. His supporters, dressed in the white and blue colours of the CNRP, shouted ‘Change!’ and ‘Number seven!’ – the party’s number on the ballot. The previous week Rainsy had received a royal pardon for a conviction many saw as politically motivated, in time to return from France for yesterday's election.

The Extraordinary Chambers in the Courts of Cambodia were set up in February 2009 to try the surviving Khmer Rouge leaders accused of being ‘most responsible’ for crimes committed between 1975 and 1979, when up to two million people died from starvation, torture and execution under Pol Pot's regime. In 2010, the prison camp commander Kaing Guek Eav was given a 35-year sentence for crimes against humanity. The trial of three other Khmer Rouge leaders is ongoing. But the tribunal is in danger of being derailed by cases 003 and 004, which involve lower ranking Khmer Rouge cadres and have been subject to intense political opposition from the Cambodian government, some of whom used to belong to the Khmer Rouge. Hun Sen, the country’s leader since 1985 and a former Khmer Rouge cadre, has spoken out repeatedly against cases 003 and 004.