The author is a Judge of the International Tribunal for the Law of the Sea. He has served as a member of the UN International Law Commission and the Chairman of its Working Group on the Obligation to Extradite or Prosecute (aut dedere aut judicare); Chairman of the UN General Assembly's Working Group of the Sixth Committee on the Administration of Justice at the United Nations; and Coordinator of the International Legal Cooperation against Terrorism stream of the Legal Issues Working Group of the Bali Regional Ministerial Meeting on Counter-Terrorism, in response to the Bali Bombing of 12 October 2002 and subsequent terrorist activities in the Asia-Pacific region and beyond.
He has held visiting professorships at some world-renowned law schools in Australia, Singapore, and the USA. His publications include the pioneering textbook International Criminal Law published by OUP in July 2001.