Blogger Cameron Slater says he was "incredulous" that a District Court judge ruled he does not meet the criteria to be considered part of the media.
The Whale Oil founder is being sued by Auckland businessman Matthew Blomfield in a defamation case and has been ordered to hand over confidential sources as part of discovery.
In September 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".
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.
Today, the blogger told Radio New Zealand when he was convicted in 2010 of breaching court suppression orders, Judge David Harvey "clearly outlined in his judgement against me...what constituted being a medium for news dissemination".
"Under that definition I quite clearly meet the requirement for being a news medium."
Slater was "incredulous" that Judge Blackie has ruled otherwise, he told RNZ.
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."
At last week's hearing, Blomfield applied to have Slater jailed for contempt of court for refusing to comply with the earlier order of Judge Blackie.
But Judge Phil Gittos said that was inappropriate.
Instead, he 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.
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."
In October, Slater broke the Len Brown sex scandal story days after Brown was re-elected mayor of Auckland.
On his blog, Slater revealed the married father-of-three had a two-year affair with aspiring politician Bevan Chuang.