The court has ordered the return of some assets belonging to Kim Dotcom and three of his associates, seized during the January 2012 raids.
High Court Judge Helen Winkelmann found police search warrants used during the raids were invalid because they could not authorise the seizure of irrelevant material.
She ordered that none of the items seized, nor copies or clones of them, be permitted to leave New Zealand and that any irrelevant material be returned to the four men.
Police said they were considering the judgement, and would work with Crown Law to determine their next steps.
"Police note that the judgement requires Mr Dotcom to provide Police with the appropriate passwords to enable Police to access the items seized (eg hard drives and laptops) in order to assess their content for relevance,'' a statement said.
"The judgement also provides for relevant material to be released to the FBI and for irrelevant material to be returned to Mr Dotcom and his associates.''