On Friday, the High Court of New Zealand ruled (PDF) that Kim Dotcom should gain access to the data seized by local police during a January 2012 raid. The decision represents yet another intermediate victory for the Megaupload founder, who is accused of copyright infringement-related crimes in the United States.

The High Court judge used some fairly strong language to describe the way in which the search and arrest warrants were issued (and how the subsequent SWAT-style raid on Kim Dotcom’s mansion was handled). “This has given rise to a miscarriage of justice,” Chief Justice Helen Winkelmann wrote in her decision.

Earlier this month, we reported on how the New Zealand Supreme Court is expected to hear an appeal to determine whether Dotcom should have access to the American evidence (in the form of documents, rather than seized data) against him. (And that’s even before local judges will determine whether Dotcom can be extradited to the United States, where he faces charges.) The entire saga has become one of the most expensive legal cases in New Zealand’s history.

Justice Winkelmann quoted from her own previous decision in which she found the warrants invalid, and she has now ruled that “in respect of items containing only relevant material, [clones of the seized data] must be provided to the plaintiffs before a clone is provided to the United States.”

In addition, she ruled, any data seized with irrelevant data should be returned. Meanwhile, “mixed content devices” should also be returned to Kim Dotcom.

Quoting from her previous decision, she wrote:

The warrants do not stipulate that the offences of breach of copyright and money laundering are offences under the law of the United States of America, nor that they are punishable by a sentence of imprisonment of two years or more. They do not refer to any statutory provision to enable the subject of the warrant to understand the nature of the offences referred to. The failure to refer to the laws of the United States on the face of the warrants would no doubt have caused confusion to the subjects of the searches. They would likely read the warrants as authorising a search for evidence of offences as defined by New Zealand's law. The only clue that they are not is that each warrant is headed “The Mutual Assistance in Criminal Matters Act 1992”. That is not much of a clue.

In the present decision, she concluded: