Murdoch joined the
Ministry of Foreign Affairs in 1972. He had an early posting to Canberra, before joining the Department of the Prime Minister and Cabinet in 1980 as foreign affairs adviser to Prime Minister
Rob Muldoon. In 1983, Murdoch was assistant head of the Asian division in the Ministry of Foreign Affairs. Later that year, he was posted to
Washington, D.C., as political counsellor, and the New Zealand intelligence liaison officer to the United States. In 1987, Murdoch returned to New Zealand and became head of the Australia Division in the Ministry of Foreign Affairs. In 1989, Murdoch was seconded to the Department of Prime Minister and Cabinet to be head of the Policy Advisory Group. In 1991, State Services Commissioner
Don Hunn appointed Murdoch to the post of Secretary of the Department of Prime Minister and Cabinet. Murdoch was head of the department of Prime Minister and Cabinet under Prime Ministers
Jim Bolger and
Jenny Shipley. He left the post in 1998, to become visiting professor of Public Policy and Management at
Victoria University of Wellington for a year. In 1999, Murdoch was appointed New Zealand High Commissioner to Australia. In the
2009 Queen's Birthday Honours, Murdoch was appointed a
Companion of the New Zealand Order of Merit, for public services, lately as Secretary of Foreign Affairs. ==GCSB==