Martin was appointed Special Adviser on Human Rights Field Operations to the High Commissioner on Human Rights in 1998, then Deputy High Representative for Human Rights in the Office of the High Representative for Bosnia and Herzegovina from 1998 to 1999.[1][2][3] During the United Nations Mission in East Timor that garnered worldwide attention in 1999, Martin served as Special Representative of the UN Secretary-General for the East Timor Popular Consultation.[1][2][5] From 2000 to 2001 he was appointed Deputy Special Representative of the UN Secretary-General in the United Nations Mission in Ethiopia and Eritrea.[1][2][5] In 2006, he served as Special Envoy of the Secretary-General for Timor-Leste.[1][2]