Shanghai Daily, August 04, 2011
http://www.shanghaidaily.com/nsp/National/2011/08/03/Beijing%2Bpolice%2Bprobing%2Balleged%2Billegal%2Bdetentions/
Related news:
北京昌平一“黑监狱”被查封 (Beijing Black Prison Shut Down)
Radio Free Asia, August 03, 2011
http://www.rfa.org/mandarin/yataibaodao/hjy-08032011161020.html