According to the BBC:
"India's outsourced call centres are well known, but not its outsourced patients. By 2010, some estimate there will be two million patients in India on clinical trials. An entire industry has sprung up, specialising in recruiting patients and managing experiments. And a BBC investigation into the conduct of these trials has found that some patients are unaware they are being experimented on at all. "
See "Drug trials outsourced to India," and a trailer for the BBC documentary.