Labour says the inquiry into who leaked documents from the Foreign Affairs Ministry has turned into a witch hunt, and should be stopped.
Paula Rebstock is leading the investigation into the leaks, which happened during consultation over job losses and changes at the ministry.
Unions have sought legal advice after the terms of the inquiry were widened, and members have been told not to speak to investigators.
MP Phil Goff says the saga has just entrenched the damage already done to staff morale by the proposed changes.
"The inquiry has taken months and frankly it's not going anywhere. If you want to know who the culprit is, for the leaking of information, look no further than the Minister of Foreign Affairs himself. He is the man responsible for getting it wrong."
Photo: Foreign Affairs Minister Murray McCully (Getty Images)