Prime minister John Key has come out fighting over Labour's spy tape allegations - calling for any recording to be made public, if it exists.
Labour leader David Shearer says Key was filmed making a joke about Kim Dotcom at a briefing in February.
But the Government Communications Service Bureau (GCSB) said it has completed an exhaustive search of its files and no official recording exists.
And Key said he couldn't remember cracking the joke. A private recording of the speech would be illegal, but Key said he gave authority for it to be released publicly.
''I am notorious for cracking jokes at events that are in the public domain. Mr Dotcom's name had been in the public domain for five weeks but there is no recording from GCSB, there has never been a recording from GCSB.''
Key said he gives more than 25 ''off the cuff'' speeches a week and would struggle to remember everything he said.
''But if the allegation for Mr Shearer is somehow that I had some secret briefing, that I was fully au fait with everything the GCSB was doing and that's what led me to crack a joke, he's utterly wrong.''
He also accused Shearer of ''utter desperation.''
''He really should apologise to the GCSB for making such claims with no backing.''
Key said GCSB had planned to film his briefing to staff in their cafe. But they changed their minds before he arrived.
Cameras, equipment logs, files and back up files had all been thoroughly checked.
''So if Mr Shearer has a private recording, which someone may have recorded on a phone or whatever, he should feel free to put that in the public domain.''
Key has admitted a reference to Dotcom was made in a ''wider'' briefing about the Bureau's work.
But he said: ''On the 17 September this year I had the first briefing that I can recall about Mr Dotcom.'' He insisted: ''I stand by everything I said.''
He didn't know who was behind the leak to Labour and an investigation at the agency was under way.
''That's a matter for the agency. The agency is notorious for very high ethical standards and if somebody has been talking about my visit that's disappointing.''
Key said he is ''free political game'' but he is disappointed the integrity of GCSB agents was attacked.
''New Zealand needs to judge me...they can either rely on my word or not. I leave it up to them.''
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