The New Zealand High Court has ordered police to sift through digital material taken from Megaupload founder Kim Dotcom and return anything irrelevant to their investigation at their own cost.
The controversial entrepreneur is attempting to fight extradition to the United States on charges of copyright infringement, racketeering and money laundering.
Dotcom has been been fighting to get the return of his material, which was illegally seized during a raid on his home last January, to help him prepare his defence.
High Court Justice Helen Winkelmann said the seizure of the devices without sorting them first was unlawful and the police have no right to keep material that is not relevant to the case. Crown lawyers had argued that the return of material was unnecessary.
Dotcom - whose real name is Kim Schmidt - is seeking damages from the New Zealand government for its role on a raid on his home in January 2012, when local police swooped on his mansion at the request of US authorities
He faces extradition for charges of leading a group that copied and distributed copyrighted material worth more than $500m (£322m).
Cloned copies of Dotcom’s hard drives sent to the FBI were deemed to have been unlawfully obtained and following the ruling his legal team asked the court to order the return of the entrepreneur's personal belongings.
The New Zealand authorities are now required to go through all the seized material in order to determine what is relevant to the ongoing prosecution and return the rest.
Judge Winkelmann rejected the argument that police made a minor technical mistake in the seizure: “The deficiencies in the warrants and, as a consequence, the searches, were more than merely technical,” she said.
“The defects in the warrants were such that the warrants were nullities.”
“The warrants could not authorize the permanent seizure of hard drives and digital materials against the possibility that they might contain relevant material, with no obligation to check them for relevance.”