Image caption Rinchen Samdrup denied posting a pro-Dalai Lama article on his website

A Tibetan environmentalist has been sentenced to five years in prison by a Chinese court, his lawyer has said.

Rinchen Samdrup, the third brother in his family to be jailed, was found guilty of inciting separatism in China, reports say.

Mr Samdrup, who had pleaded not guilty, was accused of posting a pro-Dalai Lama article on his website.

The sentence comes just over a week after one of Mr Samdrup's brothers was sentenced to 15 years in prison.

Authorities in China said an article on the Tibetan spiritual leader was posted on Mr Samdrup's website, the Associated Press news agency reported.

The website is devoted to protecting the environment in the Himalayan region.

Mr Samdrup told Changdu Intermediate People's Court that he did not post the article himself.

His lawyer, Xia Jun, was quoted as saying: "It was a mistake, but not a crime." The lawyer did not say who posted the article on the website.

The sentence comes after his brother, a nationally known environmentalist once praised by the Chinese government as a model philanthropist, was sentenced to 15 years in prison.

Karma Samdrup, 42, was found guilty of grave-robbing and dealing in looted antiquities. His lawyer said police had used false evidence.

Karma's supporters said the sentence was intended to punish his activism - including his attempts to free Rinchen and another brother from detention.

Rinchen and brother Chime Namgyal were held after accusing officials in eastern Tibet of poaching endangered species, AP reports.

International human rights groups say China has increased pressure on leading Tibetan figures since riots killed 22 people in the region in 2008.