The Supreme Court on Monday issued notice to the Centre on a writ petition alleging that illegal clinical trials of untested drugs were being conducted by pharmaceutical companies on adults, children and even mentally ill persons in various States. The Indore-based Swasthya Adhikar Manch was the petitioner. NGO's counsel Sanjay Parikh told the Bench of Justices R.M. Lodha and H.L. Gokhale that in a large number of cases, multinational corporations were using contract research organisations for carrying out clinical trials of unapproved drugs.