The Crown has told the Supreme Court that US prosecutors don't have to provide Kim Dotcom's legal team with anything more than a summary of the case against the internet entrepreneur.
The FBI is seeking to extradite the founder of the Megaupload site to face charges of copyright fraud, money-laundering and racketeering.
Mr Dotcom's lawyer Paul Davison, QC, says he is fighting to get access to evidence so that his client can have a fair extradition hearing.
But Crown lawyer Mike Heron, QC, told the Supreme Court in Wellington on Tuesday the law makes it clear only a summary of the evidence is required.
In 2012, the North Shore District Court ordered US authorities to provide an extensive disclosure of documents before extradition.
On Tuesday, Mr Heron said the District Court has no power to make that order. He said in two decades of similar claims in other jurisdictions, including the United Kingdom and Canada, that same argument has been raised and rejected.
Mr Heron said if New Zealand courts order the United States to provide more evidence, it would slow down the extradition proceeding.
Paul Davison told the Supreme Court on Tuesday that the case against Kim Dotcom is entirely circumstantial and the evidence provided so far is seriously deficient.
Under the Extradition Act, American agencies must provide only a summary of the case - which in this instance is 109 pages. But Mr Davison told the court on Tuesday that this summary is inadequate and draws conclusions without providing any of the relevant background material.
Mr Davison said the information provided does not show one piece of criminal intent and alleges illegal activity that is wholly without foundation.
He said it has been left up to US authorities to decide what to include, and argues that New Zealand courts should have the power to order a more thorough disclosure of evidence.
Five judges are hearing the case and a ruling is expected in several weeks.