Cameron Slater says he was "talking up a big game" when he claimed in an email that Judith Collins was "gunning" for the former director of the Serious Fraud Office, Adam Feeley.

The Whale Oil blogger invited media to his home in the wake of Judith Collins' resignation, reading a statement that said: "Judith Collins has now been taken down by death by a thousand cuts".

In the latest leaked email from 2011, Slater claims he spoke at length with Ms Collins, saying: "She is gunning for Feeley and asking for information on his background. The email goes on to say: "She is using this review of these events to go on a trawl looking for anything else. It is my opinion that Feeley's position is untenable."

When asked about the email he said: "If Judith Collins was gunning for someone she'd have got them", pointing out that Adam Feeley resigned from the role a year after the email was written.

When challenged on whether he was therefore lying in the email, he said "embellish is a good word. It's better than lie isn't it?"

Journalists also asked if he would "give back double" for the bringing down of his friend, he replied: "I always give back double" and "Judith always gives back double".

In his statement Mr Slater also claims Judith Collins is a victim of a large scale criminal conspiracy and said "what doesn't kill you makes you stronger and the game never ends".

My book brought down Collins - Hager

Meanwhile, Nicky Hager says Ms Collins has resigned because of the material contained in his book 'Dirty Politics' and not because of the email today.

"It's obvious she's standing down because the allegations in the book look so bad and the public weren't believing what they were saying and it wasn't going away. The email is just an excuse."

Mr Hager says Mr Key should have taken action when the book was first released.

"When I first saw the materials about Judith Collins it seemed to me that there was no way that that could be published and she would remain Minister of Justice in New Zealand, it just wasn't possible."

"This is a slippery way of doing it. They are pretending that she is not stepping down because of the book. I don't think they have done it well at all."

"Professional relationship"

The man at the centre of the latest email allegations, Adam Feeley, said in a statement today that in his years as a public servant he has worked for a number of ministers of various governments and strived to ensure an entirely professional and constructive working relationships with them.

"Throughout my time as Chief Executive of the SFO, I believe that the work of the SFO always enjoyed the support and respect of the Government," he said.