Private Detective in Sydney : NIA Leading private investigators in Sydney specialising in Private Investigations, Detective Services & background checks.National Inquiry Agency - Leading private investigators in Sydney specialising in Skip tracing, background checks, surveillance and process serving.Who do our Private Investigators Work With?We work alongside individuals and business owners to locate Debtors, assist in the facilitation of legal proceedings through surveillance and process serving, protect employer interests with employment screening, and surveillance of employees’ conduct. We