A police raid on investigative journalist Nicky Hager's home in the wake of his Dirty Politics book has been branded illegal by the High Court.
A judgement released by Justice Denis Clifford today says police failed to disclose the relevant information to the judge who issued the warrant and as a result, declared it "fundamentally unlawful" and by extension the search as well.
In a statement released via his lawyer, Mr Hager said he is "very happy" about the decision.
"The heart of the case is the public's right to receive information about the actions of people in positions of authority. This decision acknowledges that confidential sources used in investigative journalism, in this case my book Dirty Politics, deserve legal protection."
Police spent hours at Mr Hager's Wellington home on October 2 last year.
More hearings are expected on other police actions taken against Mr Hager following the book's release in the lead up to last year's election, as well as costs and damages.
Mr Hager believes this decision is the most important one and has ramifications for all media and whistleblowers.
He thanked those who supported him by donating money to cover court costs and those who helped in his case.
Dirty Politics exposed smear tactics within New Zealand politics, including the relationship between senior National Minister Judith Collins and WhaleOil blogger Cameron Slater.
It provided the backdrop to much of last year's election campaign.
The information was given to Mr Hager by a hacker known as Rawshark, who downloaded Slater's emails which provided the material for the book.
Police took computers and other "related items" as part of its investigation into the alleged hacking.