He joined the Indian Civil Service and served as Regional Commissioner for the Eastern States, a member of the Constituent Assembly of India, joint secretary for India's Defense Ministry, Director-General of Transport, and special secretary in the Ministry of Information and Broadcasting.[5]
Between 1966 and 1972 Singh was secretary to the President of India,[5] then from 1 October 1972 to 6 February 1973 he was Chief Election Commissioner of India.[6] In 1966, 1969, and 1975, he was appointed a representative of India in the United Nations Assembly and served on the United Nations International Law Commission on a part-time basis from 1967 to 1972. He was also elected as secretary of the International Bar Association. In 1973, he moved to The Hague to become a judge of the International Court of Justice and was its president between February 1985 and February 1988, when he retired.[5] He continued to live at the Hague and died there in December 1988.
^"Previous Awardees". Padma Awards, Government of India. Retrieved 4 November 2022.
^Carl Landauer, Passage from India: Nagendra Singh’s India and international law. Indian Journal of International Law 56, 265–305 (2016). https://doi.org/10.1007/s40901-017-0057-4
^Prabhakar Singh, Indian Princely States and the 19th-century Transformation of the Law of Nations, Journal of International Dispute Settlement, Volume 11, Issue 3, (2020)pp. 365–387, https://doi.org/10.1093/jnlids/idaa012.