The High Court has recently addressed the issue of common law extinguishment. Its decision in Western Australia v Brown  HCA 8 (Brown) provides guidance about the extinguishment of native title rights and interests where the Native Title Act 1993 (Cth) does not apply (generally, for acts done before 1975).
Brown concerned two mining leases granted by the State of Western Australia in 1966 and 1974. The primary question for the Court to decide was whether the leases wholly extinguished native title. The Court found that they had not on the basis that the leases did not grant the lessees a right of exclusive possession. This means that these leases are effectively in the same legal category as the pastoral leases in the Wik case (Wik Peoples v Queensland (1996) 187 CLR 1 at 87).
Key findings and comments made by the Court:
- “The question of inconsistency of rights … must be decided by reference to the nature and content of the rights as they stood at the time of the grant.” (emphasis added)
- “Extinguishment of native title does not depend upon the exercise of the allegedly inconsistent right: the inconsistency is … between the rights and not between the manner of their exercise (citing Brennan CJ in Wik).”
- “Questions of extinguishment must be resolved as a matter of law, not as a matter of fact.”
The most important message to take away from this decision is that when considering whether a non native title interest extinguishes native title to any extent, the focus must be upon the content of the right itself at the time it was granted.