International organizations — Privileges and immunities — Staff members — Exemption from taxation — Contractor — Whether taxpayer holding an office in international organization — International Organisations (Privileges and Immunities) Act 1963 (Cth), Section 6(1)(d)(i) — Proper construction of Act

Relationship of international law and municipal law — Treaties — Convention on the Privileges and Immunities of the United Nations, 1946 — International Organisations (Privileges and Immunities) Act 1963 (Cth), Section 6(1)(d)(i) — Whether construction of Act according with Australia’s obligations under Convention — Whether taxpayer holding an office in international organization — Whether exempt from taxation — The law of Australia