(1) The court must not award damages or an account of profits for infringement of a patent if the defendant proves that at the date of the infringement the defendant did not know, and ought not reasonably to have known, that the patent existed or, in the case of a proceeding under section 77, that the complete specification had become open to public inspection.
(2) It is presumed that a person ought reasonably to have known that a patent existed if—
(a) a product is marked so as to indicate it is patented in New Zealand and with the New Zealand patent number; and
(b) the person knew, or ought reasonably to have known, of the product.
(3) But there is no presumption if the product is marked merely so as to indicate it is patented.
Compare: 1953 No 64 s 68(1)