Author Nicky Hager says the person who leaked emails from former National Party leader Don Brash is happy a police investigation has failed to reveal their identity.
In late 2006, extracts from 475 separate Brash emails were used by Hager as the foundation for his book The Hollow Men.
Mr Hager has always maintained the emails were leaked to him by National Party sources and said those who claimed they were gained by theft should apologise to him.
He would not tell police the source of the emails but the National Party has rejected a mole in its ranks and still believes the emails were stolen, probably by someone who hacked into Dr Brash's email system.
Mr Hager told Radio New Zealand this morning that he continued to get material from National and other parties, but he had no plans for another book.
"I am still regularly getting information from the National Party as I do from other parties."
He said some of the sources were still in the National Party and he had recently been in contact with the people who leaked him information.
"They're happy and I am happy (that their identities would not be revealed). I couldn't do my job and reasonably expect people to give me information if the police could find out. I am very happy with the result."
The National Party is frustrated that the police inquiry failed to find who took emails from Brash.
Leader John Key believes a hacker did it, despite police ruling out a breach of the parliamentary computer system.
Wellington police district crime services manager Detective Inspector Harry Quinn yesterday said the investigation into the theft had ended without identifying who was responsible.
"How the thefts occurred still largely remains a mystery," Mr Quinn said.
The investigation established that emails created between October 2003 and November 2005 had been stolen from Dr Brash, but found no evidence of thefts since November 2005.
Mr Quinn said there was "no evidence" the thefts were perpetrated by someone involved in the administration of the computer systems, and police had eliminated the suggestion "an external computer hacker had breached the computer security within Parliament".
"There are strong indications that the emails were in printed form at the time of the theft, but with the thefts perhaps happening at any time over the two-year period it is very likely that they were stolen during several incidents," he said.
"The file is closed until someone comes forward with some compelling evidence."
Other than two tabled during parliamentary debate, police did not locate any of the original stolen emails.
Dr Brash said he was not happy with the outcome or the police investigation and was disappointed at how long it had taken police to interview "the obvious suspects".
Dr Brash said he had no idea about who had taken his emails.
But New Zealand First leader Winston Peters, who once tabled some of the emails and boasted to have a "telephone book" of them, said the leak was inside Dr Brash's office.
"I know that and so does Don Brash. Going to the police and laying a complaint was an absolute fraud," Mr Peters said.
Mr Key told reporters there was "no chance" the emails were taken by someone within National.
"I'm not actually satisfied that it hasn't been someone hacking into our system and I think it's still the most likely outcome."
Asked why he thought that, Mr Key said it was for a variety of reasons he was not going to document.
"But I don't think the level of email access was possible without somebody breaking into our system," he said.
"Some of the emails that Nicky Hager had were never printed."
Mr Key said he did not believe Mr Hager when the author said he was handed the documents by people within National.
Mr Key said he was disappointed police had not got a result but there was little National could do "other than say we're a bit frustrated".
Prime Minister Helen Clark said the theft of the emails was a "mysterious business" and the fact the police had not been able to draw any conclusions in the inquiry was "disturbing".
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