A 57-year-old Swiss man has pleaded guilty in a court in Thailand to charges of insulting the king.
Oliver Jufer faces several years in prison, his lawyer says
Oliver Jufer was arrested last December after drunkenly spray-painting several portraits of the monarch, King Bhumibol Adulyadej.
In court, Jufer pleaded guilty to five charges under Thailand's draconian lese majeste law.
He is due to be sentenced later this month, and the maximum penalty he could face is 75 years in jail.
Jufer's lawyer said the minimum sentence he faced was seven-and-a-half years.
KING BHUMIBOL ADULYADEJ
Born in 1927, ascended throne in 1946
World's longest-serving current head of state
Official powers are limited, but wields enormous influence because of popular backing
Widely believed to have given backing to 2006 military coup
Police reports said Jufer was drunk when the portraits were defaced on 5 December, which as the day of the King's birthday is a national holiday.
Jufer, who has lived in Thailand for more than 10 years, was recorded on surveillance cameras defacing the portraits.
The BBC's Jonathan Head, who was outside the court in the northern city of Chiang Mai, says the case throws a rare spotlight on the strict lese-majeste laws in Thailand forbidding any criticism of the monarchy.
At one point the prosecutor tried to get the media to leave, saying the case had been postponed.
"We don't want the Thai people to know about this case," he said.
The image of the monarchy is very carefully managed, with local media only allowed to lavish praise on the king, our correspondent says.
The popular reverence for him is genuine, but the draconian laws deter most Thais from even discussing the monarchy.
The king himself appeared to question this in a recent speech when he said it was wrong to put him above criticism.
"I am not afraid if the criticism concerns what I do wrong, because then I know," he said. "If you say the king cannot be criticised, it means that the king is not human."
But without any public debate there seems no possibility of amending the law, which allows any Thai citizen to bring a charge against anyone else for insulting the king.
A handful of other foreigners have faced similar charges in the past. Most have eventually been allowed to leave the country.