Alfred James Murdoch was born at Onehunga on 18 April 1877, one of at least five children of Mary Ann Nealis and her husband, John Murdoch, a clerk. The family lived at Opua, Bay of Islands, from 1886 and eight years later settled in the coalmining town of Hikurangi, where his father was both station- and postmaster.
Fred, as he was known, became a pupil-teacher at Hikurangi in 1896, and two years later was appointed to the part-time schools of Mata and Ruakaka. He taught at both until 1916, then solely at Ruakaka until 1919, when he became a dairy farmer and breeder of pedigree jersey cattle. That year he was also part of a delegation that visited North America and Europe to study the manufacture and marketing of milk powder, lactose and other milk products. He had married Rosina Helen Lee, the daughter of a schoolteacher, at Mangapai on 9 April 1903; they were to have three sons.
In 1919 Fred Murdoch entered politics as an Independent Progressive candidate for the parliamentary seat of Marsden. Confident in the progress of the district, and aware of the problems of farmers, miners and country schools, he advocated reform of the parliamentary system and the civil service, nationalisation of coalmines, the expansion of rural education and new public works programmes. He strongly promoted the development of Whangarei and Northland, and supported the campaign to extend the railway to Waipu. Popular, straightforward and energetic, he polled a close second to the Reform Party member, Francis Mander, who had held the seat since 1902.
In 1922, Mander having retired, Murdoch won the seat as a Liberal candidate. Although a hard-working member and a vigorous – if somewhat verbose – debater, he was defeated in 1925. Three years later, standing under the United Party banner, he returned to Parliament and became senior whip in Sir Joseph Ward's government. In 1930–31 Murdoch served as minister of agriculture and mines in the short-lived Forbes government, but although regarded as an able administrator, he made little impact as a cabinet minister. From 1931 to 1935 he was senior whip in the coalition government.
Defeated by the Labour Party's J. G. Barclay in 1935, Murdoch was appointed to the New Zealand Dairy Board, on which he served until 1948, including three years as chairman. During this time a number of uneconomic dairy factories were closed as the board moved to rationalise the industry, and a system of guaranteed prices for butter and cheese was introduced.
In 1943, standing for the New Zealand National Party, Murdoch defeated Barclay and returned to Parliament for a third term. He increased his majority at each succeeding election, but at the age of 72 was overlooked for cabinet when National assumed office in 1949. He served on the Goldfields and Mines and Maori Affairs committees, and in 1950 sat on a committee to consider the reintroduction of capital punishment. He retired from Parliament in 1954, but continued to take an active interest in local affairs, promoting, for example, the development of Whangarei's port and the building of a new post office.
An able sportsman, Murdoch had helped to found the Hikurangi Rugby Union Football Club in the 1890s and was a senior Whangarei representative in 1898. He played hockey for Ruakaka, representing Whangarei in 1920, and was a member of the Onerahi Cricket Club; in later life he was a keen lawn bowler. Rosina Murdoch was also active in the local community, serving as a committee member, and later president and patron, of the Whangarei branch of the Plunket Society; Fred was also patron for several years.
A man of integrity and energy, Fred Murdoch had a sound grasp of rural problems and was described as 'a straight, clean fighter in the political field'. He died on 1 June 1960 at Whangarei, survived by his wife and two sons. One of his sons, Lee Murdoch, was mayor of Papatoetoe (1959–65) and later served on the Auckland Regional Authority for 18 years, including 7 as chairman.