in the discretion of the Court whether or not certiorari would have
lain. That a declaration may be an appropriate remedy for both
jurisdictional errors and closely analogous defects such as unfairness
or breaches of natural justice is shown by such Privy Council and House
of Lords decisions as _De Verteuil_ v. _Knaggs_ (1918) A.C. 557, _Pyx
Granite Co. Ltd._ v. _Ministry of Housing_ (1960) A.C. 260, and _Ridge_
v. _Baldwin_ (1964) A.C. 40. The statement apparently to the contrary at
the end of the _Reynolds_ judgment at p. 40 is obsolete. And if a
declaration could have been granted that a decision made under a
statutory power is invalid the Court has power under the 1972 Act to set
the decision aside.


The Order for Costs

In argument in the present case it was common ground that if the order
for $150,000 costs is invalid the Court can set it aside. That is
clearly so. The order was made in reliance on s. 11 of the Commissions
of Inquiry Act 1908 which (notwithstanding an argument to the contrary
by Mr Harrison) is in our opinion undoubtedly the only source of any
authority for a Royal Commission or a Commission of Inquiry to award
costs. If valid it is enforceable by virtue of s. 12 of that Act as a
final judgment of the High Court in its civil jurisdiction. Plainly it
is the exercise of a statutory power of decision. The jurisdiction of
the New Zealand Courts to determine the validity of orders for costs by
Commissions is well established: _Hughes_ v. _Hanna_ (1909) 29 N.Z.L.R.
16; _Whangarei Co-operative Bacon-Curing Co._ v. _Whangarei
Meat-Supply Co._ (1912) 31 N.Z.L.R. 1223; _Pilkington_ v. _Plaits_
(1925) N.Z.L.R. 864.