"Gyaye Phuntsog is currently receiving treatment in Chabcha county hospital...following his release from custody," the London-based group said in a statement faxed to AFP.

"His legs are reportedly swollen and at least two sources state that he has been unable to walk without the use of crutches since he was released from detention," TIN said.

Phuntsog, 68, was sentenced to six years in prison in July for "damaging the stability of the nation" and released several months ago on medical parole after being ill-treated during detention, it said.

He had been active in providing basic education to poor nomadic children in his hometown of Gyaye, and had received funds from "Project Hope", a movement initiated by the China Youth Development Foundation in 1989 andpartly sponsored by UNESCO.