He served successively as assistant collector, collector, and in other capacities in Sind until 1911, when he was appointed Secretary to the Government of Bombay in the General Department.
In 1917, he was appointed Collector of Karachi, and in 1918 he became Secretary to the Government of Bombay in the Revenue and Financial Departments.
He was Commissioner in Sind from 1915 to 1925, and served on the Executive Council of the Governor of Bombay from 1926 until his retirement in 1929 as member responsible for revenue, in succession to Sir Maurice Hayward.
[1] Rieu was married firstly to Ida Augusta Edwards (died 1921), daughter of John Edwards, JP, of Knockrobin, County Wicklow; they had a daughter.
Kirkpatrick had been married to Charles William Aldis Turner, ICS, who obtained a divorce decree against his wife on grounds of adultery earlier that year, citing Rieu as co-respondent.