Both men were charged under Article 437, which criminalises any ‘speeches, gestures, writings, paintings or items’ that insult the dignity of the King. Those who are found guilty face between one and five years in prison and up to $2,500 in fines.

‘The Cabinet’s approval of a lèse-majesté law appears to be a further attempt by the government to weaponise the country’s legislation against its perceived opponents,’ said Kingsley Abbott, a senior international legal adviser at the International Commission of Jurists, when the law was going through the Cambodian Parliament.

Rhona Smith, United Nations Special Rapporteur on the human rights situation in Cambodia, called the law ‘incompatible with Cambodia’s obligations under international human rights law, as they criminalise the legitimate exercise of freedom of speech’.

The lèse-majesté law was passed by a ruling party-controlled National Assembly which, along with the Community of Royalist People's Party, holds nearly every seat following the dissolution of the main opposition party, the Cambodia National Rescue Party (CNRP), last year.

The Phnom Penh Post reported that the barber shared a post that ‘consisted of comparing King Sihamoni unfavourably to Cambodia’s former kings’, while the pro-Government Fresh News reported that the Facebook comment blamed the King and the Royal Family for the dissolution of the opposition CNRP, saying they destroyed the will of millions of voters.

In November, the ruling party-aligned Supreme Court dissolved the CNRP, which had been the only viable contender in the 2018 July elections. This came two months after the arrest of CNRP President Kem Sokha, which saw most senior party officials flee the country. Ahead of the Supreme Court ruling, the electoral law was amended to allow the CNRP’s seats to be redistributed.

While Cambodia’s monarch holds a largely figurehead position and has abstained from politics, the country’s Constitution requires that newly passed laws are approved by the King. This requirement has led to speculation that the King has timed trips to avoid signing controversial laws, including the lèse-majesté law, which was approved by the Senate President of the ruling party instead.

The arrests of Samphy and Navy come at a moment of greater self-censorship among journalists and more general suppression of free speech in the country. Last month, Cambodia dropped ten places in Reporters Without Borders’ annual World Press Freedom Index, which ranked it 142 out of 180 countries.

Since last September, dozens of radio broadcasters have been shut down, two journalists have been arrested and the English-language Cambodia Daily has closed after being hit with a $6.3m tax bill that many believed to be politically motivated. In early May, the last remaining independent newspaper, The Phnom Penh Post, was sold to a Malaysian buyer with ties to the Cambodian government.

A joint statement from scores of local and international non-governmental organisations said the lèse-majesté law was a type of ‘legal weaponry’ from ‘a government that appears determined to eliminate all forms of peaceful dissent, pluralism, and open political debate’.

‘The vague nature of the amendments means they could be misused to justify the introduction of wide-ranging sanctions punishing the legitimate exercise of fundamental freedoms, including engaging in any discussion of Cambodia’s rapidly deteriorating human rights situation,’ said the statement.

Felix Ng, the Asia Pacific Regional Representative on the IBA’s Criminal Law Committee, called the new law ‘superfluous and disproportionate’, noting that existing criminal defamation laws already provide broad coverage.

‘There is a genuine danger that such a lèse-majesté law will be abused to silence dissenting voices, and to stifle those who wish to express legitimate criticisms of the royal government,’ he said, pointing to neighbouring Thailand, where strong lèse-majesté laws have long been used to punish the outspoken to chilling effect.

Under the Thai law, those found guilty of defaming or insulting the King, Queen, Heir-Apparent or Regent can be punished by up to 15 years in prison. The wording is vague, with no definition of what an insult consists of, and the law is applied broadly and opaquely. Complaints can be filed by anyone, cases are often held in closed military courts, and those found guilty can face cumulative sentences. Last year, a Thai man was sentenced to more than 30 years in prison for posting several items on Facebook deemed to be defamatory.

‘The number of criminal prosecutions commenced by the military junta under the Thai lèse-majesté law have significantly risen since the coup in 2014, and perceived to be politically driven and to silence oppositions,’ said Ng. ‘According to the UN High Commissioner for Human Rights, only four per cent of those charged in 2016 were acquitted.’