Europa Oil (NZ) Ltd v Commissioner of Inland Revenue - [1974] 2 NZLR 737

Income tax — Assessable income — Deduction of "expenditure or loss to the extent to which it — (a) Is incurred in gaining or producing the . . . income . . .; or (b) Is necessarily incurred in carrying on a business for the purpose of gaining or producing the . . . income" — Land and Income Tax Act 1954, s 111 (Land and Income Tax Amendment Act 1968, s 12).