 Early on his career, Arunachalam's quality of work was noticed by Chief Justice John Budd Phear who recommended him to the Governor and Secretary of State.In 1887 Governor Arthur Hamilton-Gordon appointed Arunachalam acting Registrar-General and Fiscal of the Western Province, by passing 30 officers senior to Arunachalam.Fraud, corruption and inefficiency was endemic in the department and so Arunachalam successfully re-organised the department.