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.