The New Zealand Law Society says the protection of national security could sometimes justify the use of a special advocate as a last resort in some cases where national security information is kept from affected parties.
The Law Society has released its comments on the Law Commission Issues Paper National Security Information in Proceedings.
The Law Commission is looking at how to reconcile individual rights to justice with the need to protect national security. A key question is how to prevent disclosure of information that might prejudice national security while upholding principles of open justice, procedural fairness and natural justice.
One option the Law Commission considers in cases where "national security information" cannot be disclosed to affected parties is the use of a special advocate - a lawyer who is appointed to represent their interests where they are denied full disclosure of the case against them.
The Law Society says the use of special advocates does not in itself remove the unfairness inherent in a closed material proceedings regime, but can only mitigate the unfairness.
"That said, the use of special advocates may be preferable to an alternative where there would otherwise be no disclosure and no ability to represent the interests of the affected party," it says.
"However, it should always be a measure of last resort. A closed material proceedings and special advocate regime should only be used in very limited and carefully defined circumstances."
The Law Society says that in all but the most unusual of circumstances, the Crown should be able to make its decisions and prepare its case without substantial reliance on "national security information".