A Tibetan who has waged a campaign to preserve his region's ancestral language was put on trial in China for inciting separatism yesterday in a case Amnesty International denounced as "ludicrously unjust".

Tashi Wangchuk was featured in a New York Times documentary that followed him on a trip to Beijing, where he attempted to get Chinese state media and courts to address what he describes as diminishing use of the Tibetan language.

Wangchuk was put on trial at the Intermediate People's Court in Yushu, his hometown in a Tibetan area of northwestern China's Qinghai province.

The charge can carry a sentence of up to five years, but Wangchuk's lawyer Liang Xiaojun said prosecutors were expected to seek even more jail time.