He was a member of the INTOX program of the International Programme of Chemical Safety (ILO-UNEP-WHO) to prepare a computerized database on poisons, since its inception in 1988.
He is a Member of the senior advisory board to South Asian Clinical Tocicology Research Collaboration (SACTRC) (South Asian Clinical Toxicology Research Collaboration)[3] with Nimal Senanayake, Rezvi Sheriff and Janaka de Silva He has been active in the field of human rights and served as director of the Centre for the Study of Human Rights.
He was also appointed chairman of the National Dangerous Drugs Control Board and was a member of the Presidential Task Force on Child Abuse.
He has been a member of United Nations and British forensic teams (investigating the Thai Airways crash in Nepal and war graves in Bosnia) He unsuccessfully contested the Panadura seat in the Sri Lankan parliamentary elections[4] He has published papers in his own field and is the author of 12 books on subjects varying from pesticide poisoning to international relations, the best known works being A Murder in Ceylon: The Sathasivam Case, an account of the 57-day trial of this landmark case in the history of law and forensic medicine in Sri Lanka, and Sri Lanka LTTE and the British Parliament.
In a review, Professor Rajiva Wijesinghe described the book and its impact as "a measured account that will help to defuse some tensions that arose when the debate first occurred and it was assumed that this was unwarranted interference by Britishers.