A Thai court on Thursday sentenced a U.S. citizen to 30 months in prison for posting material deemed offensive to the country's royal family on his blog.

The 55-year-old Thai-born American citizen Joe Gordon was charged with insulting Thailand's royal family by translating and posting excerpts of a locally banned biography of King Bhumibol Adulyadej.

Gordon says he was living in Colorado at the time. He was arrested in May on a visit to Thailand.

A criminal court in Bangkok originally sentenced Gordon to five years in prison, but reduced the punishment because Gordon pleaded guilty in October.

U.S. Consul General Elizabeth Pratt characterized the sentence as “severe,” saying Gordon should not be punished for “his right to freedom of expression.”

The offense could have been punishable by up to 15 years in prison under Thailand's strict laws that forbid insulting the monarchy.

The United Nations and rights groups have urged Thailand to amend the controversial laws, saying they do not conform with the its international human rights obligations and have often been used to silence activists and politicians.

Observers say the government has recently filed an increasing number of charges against individuals said to have insulted the monarchy.

Last month, a Thai man received 20 years in prison for sending four “inappropriate” text messages to the secretary of then Prime Minister Abhisit Vejjajiva.

Authorities did not reveal the content of the messages, but said they were “considered insulting to the monarchy and have upset the recipients.”