Parliament has a lot of what are called 'privileges', which basically means powers and rights.
They include the right to speak freely without fear of punishment from outside Parliament, and the right to Inquire. That second one includes being able to compel people to produce documents, to summon witnesses, and to arrest (even to imprison) those who refuse to comply.
This week the outgoing Chairman of the Board of Radio New Zealand, Richard Griffin wrote to the Chairman of the Parliamentary Select Committee that has oversight of Radio New Zealand. He told the Chair, National MP Jonathan Young, "I respectfully decline the request by the Committee."
Select committees do not have the right to compel people to produce things, or to punish them for not doing so, but Parliament as a whole does. And the person who holds that power (delegated to him by the House) is the Speaker, Trevor Mallard.
A committee can ask the Speaker to exercise that right on its behalf, and the Speaker can decide to have the Serjeant-at-arms (who is kind of Parliament's ceremonial policeman) deliver a summons.
A refusal to comply would be a challenge to the authority of Parliament and Parliament has substantial power to flex in the case of a refusal.
In 1896 Parliament demanded information from the head of the BNZ, which he refused to give. The House fined him 500 pounds, which in today's money has the purchasing power of well over a million dollars.
With the possibility of the request to Richard Griffin still dangling in the air, The House sat down with the Clerk of the House of Representatives, David Wilson, to discover the fine points of these powers, and the history of their use in New Zealand. Listen to the audio for the details.