Cambodia's King Norodom Sihamoni pictured with Queen Mother Norodom Monineath
Cambodian police plan to arrest three suspects who are accused of doctoring an image of the country's sovereign to place him in a gay porn scene, along with the words "Cambodia King is gay".
The picture was posted on Facebook on Christmas Day, and seen in both Cambodia and Thailand.
It is being viewed as a rare public insult against King Norodom Sihamoni.
The monarch, who became king in 2004, is largely respected by the public and seen as being above politics.
While the monarchy in neighbouring Thailand is protected by a lese majeste law that outlaws any criticism, there is no similar law in Cambodia.
However, the country's constitution says the king is "inviolable" - or too significant to be treated with disrespect.
more Cambodia hunting suspects over doctored porn image of king - BBC News