Labour MP Phil Goff has accused Prime Minister John Key of having a direct hand in the release of intelligence documents to blogger Cameron Slater for the purposes of embarrassing the former Labour leader.
Inspector-General of Intelligence and Security Cheryl Gwen began hearings today as part of her inquiry into the release of information from the New Zealand Security Intelligence Service (SIS) to Mr Slater in 2011.
The inquiry stemmed from allegations made in Nicky Hager's book Dirty Politics, in which the author claimed the decision to release an Official Information Act document was politically motivated and Mr Slater was tipped off in advance about the exact contents and timing of the release.
The document showed Mr Goff had been briefed on Israeli backpackers the SIS had initially suspected were spies - a meeting he did not recall at the time.
Speaking to the inquiry under oath, Mr Goff said his suspicion at the time was that material was disclosed to Mr Slater to help him make an OIA request.
"Evidence for this is the specificity of Mr Slater's request, even asking for any diary notation, his statement that he knew that the request was to be expedited expecting the documents to be released immediately, and his statement in a leaked email that he had been 'sworn to secrecy' about what he knew.
"The obvious explanation was that he had a source for this information which in the nature of SIS briefings could only have been either within the SIS itself or the Prime Minister or his Office."
Mr Goff said it was unlikely that the SIS was the source because this "would represent improper conduct". He went on to say that the Prime Minister and his staff had close links to Mr Slater and his blog Whaleoil.
"No one in the Prime Minister's office would provide inside knowledge of what the SIS was saying or doing without the implicit or explicit approval of Mr Key," he said.
Mr Goff, when told by SIS director Warren Tucker that the documents would be released to Mr Slater, asked for the release to be delayed several days.
The Labour MP said it was unprecedented for a request to be turned around so quickly, and it was unwise for the SIS to have been drawn into a highly politicised debate.
In his time as Minister of Foreign Affairs, Minister of Defence, and Leader of the Opposition, he maintained the "total confidentiality" of briefings from intelligence services.
"This convention was broken, first by the Prime Minister when he referred publicly to a briefing from the SIS in relation to Israeli backpackers who were suspected to have connections with Mossad, the Israeli Intelligence Service, that he says I was given."
Mr Goff said the inquiry should look into the full political context of the matter and how information that would normally be kept secret was brought into a political debate.
Mr Key is not scheduled to appear before the inquiry, but several of his staff including chief of staff Wayne Eagleson and former adviser Jason Ede are expected to appear at the hearings.