"It is necessary to sound a cautionary note when considering this
question. When investigations are proceeding into alleged tax evasion
on a large scale it may be impossible to define documents in search
warrants other than in rather general terms. If the terms are so
general or vague as to suffer from the vice of a general warrant then
plainly it is bad; but it must be remembered that at the time the
warrant is issued the matter is obviously at an investigatory stage and
there will not be sufficient evidence in a form admissible at a criminal
trial to prove the alleged offences. The purpose of the search is to
obtain such evidence. It is necessary to reconcile the two competing
public interests that offences involving tax frauds should be detected
and punished on the one hand and the right of the individual to
protection of the law from unjustified interference with his privacy and
property on the other. It is in the public interest that those who
commit offences involving fraud in relation to tax should be brought to
justice. It is at least equally in the public interest that individual
liberty should be protected by the courts whose function it is to
protect individuals from abuse of power by the Executive arm of
government. The balancing of the claims of the due administration of
justice and those of the citizen whose rights must be jealously
protected is not determined in a sterile vacuum but with due regard to
the legislation involved and criminal activity suspected. The
complexity of taxation frauds which often involve numerous persons and
entities, and the concomitant difficulties associated with the gathering
of documentary evidence to support the laying of charges highlights the
dangers of too readily striking down warrants on the ground of
generality in cases of this kind: see generally R v InLand Revenue
Commissioners; Ex parte Rossminster Ltd [1979] UKHL 5; (1980) AC 952, especially per
Lord Diplock at p 1010."