Police plan to examine the implications to some cases currently before the courts as a result of the Supreme Court's decision to dismiss evidence collected as part of the 2007 Uruwera raids.
Illegally-obtained evidence resulted in the Crown dropping the charges against 13 people, leaving four to face trial next year.
The Supreme Court found the use of hidden cameras was illegal and the police trespassed on Tuhoe land to obtain the evidence.
Assistant Commissioner Malcolm Burgess says the ruling may impact on evidence that has been gathered in several cases now before the courts.
He says there are several cases which the police will be looking at.
Auckland University Law Professor Bill Hodge says the decision could impact on other modes of gathering evidence because the police frequently get search warrants and collect surreptitious evidence.