A New Zealand judge on Friday ordered police to return any digital material seized in an armed raid on Internet mogul Kim Dotcom's mansion last year not directly related to the prosecution against him.
The decision by High Court chief judge Helen Winkelmann follows a ruling last year that the January 2012 raid on Dotcom's Auckland mansion was illegal because the search warrants used were too broad to be considered reasonable.
Digital material such as computer hard drives were taken in the dawn swoop as part of a US probe into allegations of massive online piracy by Dotcom's now-defunct Megaupload empire.
Winkelmann ordered police to review all the material, at their own expense, to identify material that was irrelevant to the prosecution case, then return it to Dotcom.
She rejected the argument that the police had committed only a technical breach of the law and should not have to sift the material for irrelevant data, which they said would be a lengthy and expensive exercise.
"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 plaintiffs are entitled to relief."
She also said the police must provide Dotcom with clones of material that had already been sent to the FBI.
Dotcom's US-based lawyer Ira Rothkin tweeted that his legal team was analysing the decision.
US authorities allege Megaupload and related file-sharing sites netted more than $175 million and cost copyright owners more than $500 million by offering pirated copies of movies, TV shows and other content.
The US Justice Department and FBI want Dotcom to face charges of racketeering, fraud, money-laundering and copyright theft in a US court, which could see him jailed for up to 20 years.
Dotcom and his three co-accused deny any wrongdoing and are free on bail in New Zealand ahead of an extradition proceeding scheduled for August.
Explore further: US attorney general defends Dotcom prosecution