A blogger who broke the Len Brown sex scandal story has been ordered to reveal confidential sources after a judge ruled his site was not a "news medium".
The landmark ruling was made in a defamation case against Cameron Slater, founder of the Whale Oil site, who is being sued by Auckland businessman Matthew Blomfield.
In October, days after Brown was re-elected mayor of Auckland, Slater revealed the married father-of-three had a two-year affair with political wannabe Bevan Chuang.
Judge Charles Blackie said Slater was not entitled to rely on journalists' rights to protect the identity of sources, as set out in the Evidence Act.
In a ruling made on September 26, Blackie said Slater's blog was "not a news medium within the definition of ... the Evidence Act.
"It is not a means for the dissemination to the public or a section of the public of news and observation on news".
Blackie cited the Law Commission's report News Media Meets 'New Media' which described blog sites as often "highly partisan" and "highly offensive and personally abusive".
The ruling could open the floodgates for others to sue the right-wing blogger for defamation to find out who has given him information.
At a hearing in the Manukau District Court last week, Slater said he intended to appeal against the decision, and was given 28 days to file proceedings with the High Court.
Judge Phil Gittos ordered Slater to present the identity of his sources in the Blomfield defamation case to the court, to be sealed in a file pending the outcome of the appeal.
The defamation case arose from stories Slater wrote last year which Blomfield claimed were defamatory.
Slater told the court a source gave him a hard drive belonging to Blomfield, which he used to write much of the material.
Blomfield said that by accessing Slater's emails he would be able to determine whether they were written with malice, a key consideration in determining defamation.
And he argued Slater had "none of the checks and balances" of a news organisation.
"He sits at his computer and hits send."
Blomfield applied to have Slater jailed for contempt of court for refusing to comply with the earlier order of Judge Blackie.
Judge Gittos said this would not be appropriate.
Slater said his resources had been "expired" fighting the charges, and he could no longer afford legal representation after spending tens of thousands of dollars on legal fees.
"There is little doubt that I am part of the media. I will strenuously defend my right to protect my sources."
Wellington media lawyer Steven Price said the thrust of the Law Commission's report was that bloggers who were serving the functions of free speech and a free press should be treated as media and be entitled to media privileges.
"Still, it is concerned that the reporting be dispassionate and reliable. It can be argued that Whale Oil doesn't measure up on that criterion."