The Green Party has lodged a complaint with the police watchdog after a court found a raid on journalist Nicky Hager's house was unlawful.
The party has asked the Independent Police Conduct Authority to investigate whether police had been negligent or if there was any misconduct in obtaining their warrant for the search.
Last week a High Court judge ruled the 10-hour search of Mr Hager's house was "fundamentally unlawful" because police failed to disclose they were seeking a warrant for investigating a journalist.
In a letter to the IPCA, Green Party co-leader Metiria Turei said the ruling raised concerns about media freedom and conflicts between surveillance laws and protections granted under other legislation.
"There are many unanswered questions from the Dirty Politics scandal, and why the police made the decision to search Mr Hager's home is one them," she said.
She said it was possible the search had been politically motivated because the book attacked the National Party and this needed to be investigated.
"There are fundamental issues of democracy at stake here, particularly around the rights of the media to operate free from political interference or control."
But Police Association president Greg O'Connor on Monday called claims of political influence "ridiculous".
A spokesman for the IPCA said it had received the complaint and was now considering the appropriate course of action to take.
The search at Hager's home took place in the aftermath of the release of Hager's book, Dirty Politics, which was based on information taken from WhaleOil blogger Cameron Slater's emails and online communications.
The data was given to Hager by an anonymous hacker and the search was part of the ongoing police investigation to identify that person.
Hager sought a judicial review of the way police applied for a search warrant, the subsequent granting of the application, and the way the search was carried out.