A Vietnamese court Wednesday sentenced a French-Vietnamese activist to three years in prison on charges of subversion.

Pham Minh Hoang was convicted after a half-day trial of “carrying out activities aimed at overthrowing the people's administration.” Authorities say he posted several anti-government articles on the Internet, and had ties to Viet Tan, a pro-democracy group that is banned in Vietnam.

Hoang's wife said she believes her husband was being held due to his opposition to a Chinese-run bauxite mine in the Central Highlands, which activists say has caused environmental degradation in the area.

Hoang is a Vietnamese-born math professor who lived for several years in France, and holds French citizenship.

He will receive credit for the one year he has already spent in detention awaiting trial. But he faces another three years of house arrest following the end of his prison term.