PHNOM PENH • Cambodian police yesterday said they planned to arrest three suspects, including one believed to be in Thailand, for being behind an offensive photoshopped image of the country's king that placed him in a gay porn scene.

The image, which appeared on some Facebook accounts in both Cambodia and Thailand this week, is a rare public insult aimed at King Norodom Sihamoni, a monarch who is largely respected and deemed above the country's political fray.

In contrast to neighbouring Thailand, which outlaws any criticism of its monarchy, often handing down decades-long sentences, King Sihamoni is not shielded by a specific lese majeste law.

But the country's Constitution describes him as "inviolable".

General Khieu Sopheak, spokesman for the Cambodian Ministry of Interior, confirmed an investigation had been launched. "We have got orders to arrest them," he said. "If we don't take action against them, more people might follow their act."

He declined to specify which law the three suspects might have broken but said: "The King represents the whole nation and they are insulting the King, which is like they are insulting the whole nation."

Two suspects were believed to be in Cambodia with the third thought to be in Thailand, he added, saying the authorities would consider asking for help from Bangkok.

King Sihamoni ascended the throne in 2004 following the abdication of his father, King Norodom Sihanouk. Observers say he has ruled quietly as a constitutional monarch, fulfilling a symbolic role as head of state and, unlike his father, staying away from domestic politics.

The King speaks French, Czech and English after spending much of his adult life abroad pursuing a career in the arts - including establishing his own ballet company - before taking the throne. He is unmarried and has no children.

AGENCE FRANCE-PRESSE