A former Thai magazine editor has been sentenced to 11 years in jail for defaming the country's king.

Somyot Prueksakasemsuk, 51, was charged in April 2011 with lese majeste over two articles published in the now-closed Voice Of Taksin magazine.

The magazine was shut down by Thai authorities shortly before Mr Somyot's arrest.

Mr Somyot pleaded not guilty to the charges because he only edited and did not write the articles.

The writer was not charged.

In a statement to the court Mr Somyot also argued that His Majesty, the King of Thailand had previously said that he did not object to criticism.

Thailand's strict lese majeste law prevents criticism of the monarchy.

Mr Somyot was arrested after he collected 10,000 signatures on a petition to change the law.

The European Union said it was "deeply concerned" by the sentence imposed on Mr Somyot.

"The verdict seriously undermines the right to freedom of expression and press freedom," the EU delegation in Bangkok said in a statement.

Amnesty International, which considers Mr Somyot to be a "prisoner of conscience", described the court ruling as "a serious setback for freedom of expression in Thailand".

Mr Somyot is a supporter of the Red Shirt protest group, which is broadly loyal to ousted former premier Thaksin Shinawatra.