BANGKOK -- It has become almost routine in Thailand for judges to hand down jail sentences to those convicted of offending the country's king. But an unusual ruling issued on Thursday appears to considerably broaden the interpretation of Thailand's already restrictive lèse-majesté law.
In sentencing a former protest leader to two years in prison, a court ruled that the defendant was liable not only for what he said, but also for what he left unsaid.
The criminal court's ruling said the defendant, Yossawarit Chuklom, had not specifically mentioned the king when he gave a speech in 2010 to a large group of people protesting the military-backed government then in power.
But by making a gesture of being muzzled -- placing his hands over his mouth -- Mr. Yossawarit had insinuated that he was talking about the king, the court ruled.
"Even though the defendant did not identify His Majesty the king directly," the court ruled, Mr. Yossawarit's speech "cannot be interpreted any other way."
Thailand's law against insulting royalty, or lèse-majesté law -- one of the world's most restrictive -- has been invoked frequently as King Bhumibol Adulyadej, 85, enters his twilight years.
In recent years, dozens of people have been convicted of insulting the king and his family. Among them are a Swiss man sentenced to 10 years in prison in 2007 for defacing posters of the king; a naturalized American citizen convicted in 2011 for translating a banned biography of the king, which asserted that he has been more involved in politics than is generally recognized in Thailand; and a Thai truck driver who received a 20-year prison term for sending explicit text messages that insulted the king and queen.
The judgment on Thursday appears to have been the first time that someone was convicted of implying an insult, said the defendant's lawyer, Thamrong Lakdaen.
"There was no mention of the king's name in the speech," Mr. Thamrong said. "It's all interpretation."
Mr. Thamrong said the court used "speculation" to convict his client.
Thai law calls for prison sentences of up to 15 years for "insulting, defaming or threatening" three members of the royal family: the king, the queen and the crown prince.
Mr. Yossawarit, the defendant, is an adviser to the Commerce Ministry. In 2010, he was a leading member of the "red shirt" movement, which was seeking the dissolution of the government of Prime Minister Abhisit Vejjajiva.
Mr. Yossawarit told protesters in March 2010 that a number of people opposed the dissolution of the government. He named the military and the head of the privy council, among others.
But there was also someone else, he said, then placed his hands over his mouth. "I am not brave enough to say it," he told the crowd. "But I know what are you thinking right now. So I will keep my mouth shut."
The court ruled that it was obvious whom Mr. Yossawarit was talking about. During the trial, Thais with no apparent connection to the case were called to the stand and asked to whom they thought he was referring. All of the witnesses said, "The king."
Mr. Yossawarit initially pleaded guilty to the charges -- a common tactic by those seeking a royal pardon. But he changed his plea and contested the case. He plans to appeal Thursday's verdict, his lawyer said.
The government has established a special unit that monitors the Internet for royal insults. Recently, official censors blocked access to a Web page that reproduced the text of the historical document that ended the absolute monarchy in the country in 1932.
The king has resided in a special suite of a Bangkok hospital since 2009.
This article originally appeared in The New York Times.