The police are taking the investigative journalist Nicky Hager to court in a bid to access information he wants kept secret.
The police searched Mr Hager's home earlier this month looking for the source material for his book, Dirty Politics, which alleges underhand activity by National Party politicians.
The matter was the subject of a closed telephone conference before Justice Venning in the High Court at Auckland today.
Mr Hager's lawyer, Felix Geiringer, said the police seized items in the search of his client's home.
However, they were sealed with the High Court when Mr Hager claimed they were privileged.
The police are now asking a High Court judge to let them review the documents.
In a separate legal bid, Mr Hager's lawyers plan to challenge the legality of the search warrant used on three fronts: the legality of the decision by police to apply for the warrant, the granting of the warrant by a judge and the execution of the warrant by the police.
Mr Hager has had help with his legal fees from The Freedom of the Press Foundation, whose directors include Glenn Greenwald and whistleblowing former spy Edward Snowden.
They have urged people to donate and, as of this afternoon, more than $56,000 had been raised.