The arrest of a teacher under Cambodia’s lèse majesté law has been condemned by analysts and human rights defenders, who have claimed it violates freedom of expression, as government officials warned media outlets on the republishing of content deemed insulting.

On Sunday, Khean Navy, the principal of a Kampong Thom primary school, was arrested and placed in pretrial detention for insulting the King ahead of his birthday after blaming the monarch for last year’s dissolution of the opposition CNRP and “the loss of Khmer land”.

He was charged under the amended Article 437 of the Criminal Code, which could result in a prison term of between one and five years. His case came as Cambodia was kicking off a three-day celebration marking the King’s 65th birthday on Monday.

After the arrest, Fresh News published the story accompanied by a screenshot of the comments made by Navy.

This drew a reaction from Khieu Kanharith, the minister of information. He took to Facebook to say: “I think the [insulting] message republished by Fresh News will attract many more readers than the original post by the teacher,” warning news media should not republish such content.

Kanharith’s claim was endorsed by Deputy Secretary of State Ouk Kimseng, who said media outlets could face action.

“For legally registered media, the authorities will take action accordingly,” Kimseng said. When pressed for clarification, he said news media could elaborate but not “repeat the offending content or attack or insult the King”.

In Thailand, which is known for its deployment of a lèse majesté law, repeating any alleged royal insults can be grounds for prosecution.

Kimseng also warned social media users not to spread any insulting messages, saying it would make the public confused. “This would make us participate in spreading that message and, according to law, this is an offence,” he said.

Chin Malin, a spokesperson at the Ministry of Justice, said republishing an insulting message would be a crime only if a prosecutor decided it had been done “with bad intention”.

“If professional media has the intention only to describe the fact and publish that to the public so that they understand what happened, that would be fine. But it is regarded as a crime if there is bad intention, which means with the intent to attack the King – to look down on a state institution, on the King, that would give that media criminal responsibility,” Malin said.

Political analyst Lao Mong Hai said the arrest of the teacher was a violation of freedom of expression and outlined what action could be taken in such a situation.

“I would claim that I was exercising my freedom of expression, request the court shows the King’s complaint against me, and question the constitutionality of a law punishing insulting the King when it was enacted by an unconstitutional National Assembly,” Mong Hai said.

The analyst added that he would also lodge a complaint with the UN committee monitoring the right to freedom of expression to condemn any punishment as a violation of this right.

King Sihamoni, who took the throne in 2004, is considered a purely symbolic head of state who is largely above the political fray.

Brad Adams, Asia director at Human Rights Watch, said: “This is a very unfortunate development and a clear violation of freedom of expression, an important human right contained in many international human rights conventions ratified by Cambodia.”