The Green Party says the Government Communications Security Bureau needs to explain in more detail how the Waihopai spy base in Marlborough works.
The bureau has rejected accusations that it's contributing to torture, war and the use of weapons of mass destruction in Iraq.
Air Marshal Sir Bruce Ferguson and Warren Tucker, the current and former directors of the bureau, say nothing has been done at Waihopai which conflicts with Government policy on the Iraq war.
But Green Party foreign affairs spokesperson Keith Locke says just asking for the public's trust is not good enough.
He says Waihopai is linked with other spy bases around the world and the idea that it excludes specific information seems to run contrary to common knowledge.
