The Supreme Court will today hear a final plea from Kim Dotcom and three others to reject a court ruling they must be extradited to the United States to face charges connected to the operation of the defunct Megaupload website.
The hearing comes more than seven years after they were arrested in New Zealand on a United States' indictment based on an FBI allegations of massive copyright abuse which cost movie and music producers US$500 million (NZ$750m).
Dotcom, Mathias Ortmann, Bram van der Kolk and Finn Batato have all denied any wrongdoing.
They were arrested in January 2012 as part of a worldwide FBI operation of simultaneous raids that targeted bank accounts and data.
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Of the three other accused worldwide, one has pleaded guilty in a deal by which he served a year in prison and offered testimony against his former Megaupload colleagues,
The website offered users the ability to upload and access movies, music and other files. It once claimed to produce 4 per cent of the world's internet traffic and won high-profile endorsements from stars such as including Sean "Diddy" Combs and Kim Kardashian.
It brought in huge amounts of cash through membership and advertising. Documents showed Dotcom earned $40m from it in 2010.
The Supreme Court hearing is the final appeal recourse to a decision from the North Shore District Court in 2015 that the United States have shown cause for the four men to be extradited.
If it does uphold the decision, it would then fall to Minister of Justice Andrew Little to endorse the extradition warrant with his signature. If it reaches that stage, it is expected the accused would seek a judicial review of the decision at High Court, and further appeals would likely follow.
In an unusual move, the Supreme Court has released a summary of the case's path through the courts before today's hearing.
The briefing was intended to provide a solid understanding of a case which has become bogged down in wide-ranging legal argument and frequent appeals.
It laid out the progress of the extradition decision since the district court decision, with an unsuccessful appeal to the High Court. There, it was found the extradition offence did not have to be a crime in New Zealand as well as the United States.
It was a ruling which was necessary for the extradition to proceed, because the High Court also found online provision of copyrighted material was not a criminal offence in New Zealand.
It found, and the Court of Appeal upheld, the nature of the conduct of those before the court lined up with other New Zealand laws, and so qualified for extradition.
The Court of Appeal also pushed back the accused's argument the US needed to show the alleged copyrighted works actually had copyright at the time.
The arguments before the Supreme Court remain much the same - whether the court was right to focus its approval of the extradition on conduct rather than a precise reading of the law.
It was also asked to consider again the decision to look past the copyright status of the material subject to the offending to the behaviour around it.
The final considerations were on whether the evidence presented by the US warranted a trial, and the claim from the accused the district court judge had made his mind up before giving his decision.
The hearing is expected to run for four days.