BANGKOK: A prominent Thai labour rights activist and magazine editor was sentenced to a decade in prison Wednesday for violating much-debated laws designed to protect Thailand's royal family.  

The verdict came despite repeated calls by rights groups to free Somyot Pruksakasemsuk, who has been jailed since 2011.

It also underscored the harsh nature of Thailand's lese majeste laws, which have been criticised as a violation of free speech.

The articles in question were published under pseudonyms in Somyot's now-defunct Voice of Taksin magazine, which he launched in 2009 to compile political news and anti-establishment articles from writers and contributors.

Judges found both articles in question contained content that defamed the royal family and argued that Somyot, as a veteran editor, knew that and chose to print the stories anyway. The court handed down two five-year jail terms — one for each story.

Somyot said he would appeal the verdict but would not seek a royal pardon.

Although Somyot's articles were published in 2010, he was only arrested the following year after launching a petition drive to revoke Article 112 of the nation's criminal code, which mandates three to 15 years in jail for ''whoever defames, insults or threatens the king, the queen, the heir to the throne or the regent''.

''The courts seem to have adopted the role of chief protector of the monarchy at the expense of free expression rights,'' Brad Adams, Asia director of Human Rights Watch, said in a statement.

''The court's ruling appears to be more about Somyot's strong support for amending the lese majeste law than about any harm incurred by the monarchy.''