Police arrested singer Chai-amorn Kaewwiboonpan, aka Ammy The Bottom Blues, in Ayutthaya province early on Wednesday for allegedly setting fire to a portrait of the King.

Police said Mr Chai-amorn was taken into custody at a rented room about 12.40am. The singer requested he be transferred to a hospital.

Police on Tuesday denied reports that the singer had been arrested.

The deputy police commissioner said legal action would also be taken against other people, after a video of the incident was shared.

Police said they had witnesses and forensic evidence to charge Mr Chai-amorn with participating in the portrait burning. The singer was the only suspect in the case arrested so far. He had not admitted to the crime.

Mr Chai-amorn and two others are facing charges of arson, royal insult and computer crime.

The charges carry severe penalties -- 5-20 years, life in prison or death for arson; 3-15 years for royal insult; and five years each for trespassing on a state office and for computer crime.