Prime Minister John Key refuses to answer questions on the appropriateness of Justice Minister Judith Collins leaking information to a blogger.
In Nicky Hager's book, Dirty Politics, released last week, Hager alleges Collins and WhaleOil blogger Cameron Slater were behind an attack campaign that led to public servant Simon Pleasants receiving death threats.
Collins on Friday admitted giving Slater the identity of Internal Affairs official Simon Pleasants. She thought he was responsible for leaking information to the Labour Party about Finance Minister Bill English's taxpayer-funded accommodation allowance in 2009.
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Pleasants was targeted on WhaleOil the day after Collins emailed Slater saying: "Simon Pleasants, manager, ministerial property".
Police became involved after death threats were directed towards Pleasants, his wife and children. Pleasants has denied leaking anything.
Key is standing by Collins, and said he did not know all the details of the scenario, so would not go into it.
"I don't know all of the details behind all of that," Key said on Radio New Zealand's Morning Report today.
"What I do know, is that it [the book] is a series of selective pieces of information, many of which can't be backed up."
The allegations were a "smear campaign" from the Left, he said.
Key denied Jason Ede had run a "dirty tricks" campaign when he worked for the prime minister's office.
Key said he did not know Ede had accessed private information about Labour Party donors on their website.
"I probably should have known, because there was some correspondence between National and Labour that a person had," Key said on TVNZ's Breakfast programme.
But he denied the claim that National had "hacked" the website, arguing that a lapse in security meant anyone could access it.
"The point is, if the Wallabies left up on their public site their starting 15 on Tuesday, would the All Black management go and have a look?"