The Auditor-General is the head of the Nigeria Audit Service, which is Nigeria’s supreme audit institution (SAI) and is responsible for auditing government revenue and spending. The role of Auditor-General is set out in Article 187 of the Constitution of Nigeria and this was extended by the Audit Service Act 2000 (Act 584). The role includes the following:

• To approve the form of the public accounts of Nigeria and other public offices
• To audit and report on the public accounts of Nigeria and of all public offices, including the courts, the central and local government administrations, of the Universities and public institutions of like nature, of any public corporation or other body or organisation established by an Act of Parliament
• To report to Parliament within six months of the end of the financial year, drawing attention to any irregularities in audited accounts or any other matters of significance
• To report to Parliament on the six-monthly statement produced by the Bank of Nigeria which sets out the foreign exchange receipts and payments during the period, and transfers inside and outside of Nigeria
• To issue observations to the Controller and the Accountant-General or management, following the audit of an organisation
• To carry out special audits or reviews they consider necessary in the public interest, and submit reports on these to Parliament

In order to carry out these responsibilities, the Auditor-General has certain rights and duties which are also set out in the Constitution. These are:

• access to all books, records, returns and other records relating to or relevant to the accounts,
• not to be subject to the control of any other person or authority when carrying out their duties, and
• the ability to discharge any item of expenditure which is contrary to law and surcharge.