Kim Dotcom's legal team say New Zealand's extradition agreement with the United States does not remove the internet tycoon's right to see the evidence against him.
Paul Davison, QC, told the Supreme Court today the law clearly stated that extradition to the US should not just be a rubber-stamping procedure for the courts.
Kim Dotcom and three others from the defunct Megaupload cyberlocker site face extradition to the US on charges of criminal copyright violation.
The extradition hearing has been delayed until next April for a range of legal bids, including the current application to view evidence held by the FBI.
The District Court ordered disclosure be made of the evidence, backed up by a High Court ruling.
The Crown's success in appealing against that judgement has led to today's Supreme Court hearing in Wellington.
Mr Davison said the US sat in a different class of extradition than that of nations to which New Zealand was closest.
He said nations including Australia allowed for automatic extradition where an accused's fate relied on the court processes of the country seeking extradition.
But he said the US sat in a different class in which documents showing there was a case to answer were presented to court to show there was a basis for extradition.
The documents presented had to be backed up by the relevant evidence, he said.
The Crown is yet to make its submissions but has said in earlier hearings the extradition process relied on trust in the respective legal systems of the country involved.
It meant New Zealand courts were able to take on faith that there was evidence to support a case, but that it should be presented in the US.