"We certainly regret that action and it is something that we continue to talk to China about," State Department spokesman P J Crowley told reporters.
The spokesperson was responding to questions about a leading Tibetan environmentalist and philanthropist, Karma Samdrup, his two brothers, two cousins, other relatives and supporters who have been targeted and imprisoned despite no alleged evidence of political activities.
The three brothers, who are now in custody and facing charges, had been regarded as model citizens and previously acclaimed in the Chinese state-run media for their environmental and cultural work.
Karma Samdrup, a 42-year old businessman, well-known collector of Tibetan art and founder of the award-winning Three Rivers Environmental Protection Group, appeared in a court in Xinjiang on Thursday.
He was detained following unsuccessful efforts to secure the release of his two brothers Chime Namgyal and Rinchen Samdrup, who were imprisoned on August 7, 2009 after accusing local officials in eastern Tibet of poaching endangered species.
In a blog written after her attendance at the trial and posted online today, Karma Samdrup's wife Dolkar Tso wrote: " paused for a while, 'Today my friends and relatives are here, and there is probably a lot I shouldn't say.'
The account we heard afterwards exceeded our worst imaginations, we heard about hundreds of different cruel torture methods, maltreatment around the clock, hitherto unheard of torture instruments and drugs, hard and soft tactics, and even of fellow prisoners being grouped together to extract a confession.
"If he did not reveal certain details he would be mentally tormented. If he wanted to eat or go to the toilet he had to write an 'IOU', an 'IOU' which has already amounted to 660,000 RMB (USD 96,864).
"The 'purchased' food would first be crushed by people using their feet, there would be beatings for no reason, this was common and occurred too many times to count.
He said in a sad voice that he had already prepared for death and he had written a letter to tell his relatives what to do. Two elderly interpreters had red eyes and started crying bitterly." The blogpost, entitled "Praying" is translated from the Chinese by the website High Peaks Pure Earth.