The Chief High Court Judge has ruled that New Zealand authorities failed to properly carry out two major aspects of the case against internet millionaire Kim Dotcom.
Justice Helen Winkelmann considered issues relating to a judicial review of the Megaupload founder's internet copyright and extradition case, and ruled that the search warrants used by police were invalid because they were too vague.
Now police say they are in discussions with Crown Law to determine what further action might be taken and will make no further comment until that process was complete.
Mr Dotcom and three other men were arrested in January when 70 police raided the mansion during an investigation into his Megaupload website.
The men are alleged to have illegally copied and distributed music, movies and other copyright content worth millions of dollars.
Mr Dotcom's lawyers say his company simply offered online storage.
Justice Winkelmann found the warrants police used when they seized property from Mr Dotcom's mansion were illegal.
She also ruled moves by the FBI to copy data from Mr Dotcom's computer and take it offshore were also unlawful.