Below is an article published by Tibetan Review:

The Chinese authorities in Tibet Autonomous Region (TAR) had imposed tough new restrictions on Tibetan prisoners and detainees, banning all visits from families and friends, said the exile Tibetan administration at Dharamsala on its Tibet.net website May 3 [2012[. It said the new restriction order was contained in an internal notice sent to all the prisons and detention centres in the TAR in Mar 2012.

The notice was said to emphasize the need for stricter vigilance in the prisons and to direct all the prison officials to closely monitor the movements of Tibetan prisoners. The main reason for the tight new restriction was not clear, with the notice said to speak only of the need for public security and ensuring the welfare of Lhasa residents.

The Chinese authorities in Tibet usually never permit family or friend visits to detainees. Sentenced prisoners are usually permitted such visits, although with numerous exceptions, especially in the case of disappeared prisoners or detainees.

The notice was said to explain that lawyers and legal advisers of prisoners should seek permission only from the chief warden and were allowed only limited time for case discussions.

Most of the detention centres and prisons of the TAR, built in 1983, are situated in the north west of capital Lhasa, said the Tibet.net report, with most of them now being used as secret detention centres for holding political prisoners and dissidents, including many respected monks from the three main monasteries of Tibet.