Kim Dotcom's lawyers say the law would be paying lip service to his legal rights if he is denied access to evidence before an extradition hearing.

Dotcom, Finn Batato, Mathias Ortmann and Bram van der Kolk, all based in New Zealand are wanted in the United States on internet piracy charges over Dotcom's Megaupload website.

Prosecutors are appealing a ruling by Auckland District Court Judge David Harvey saying the US must disclose its information against the quartet so they can defend themselves adequately at the extradition hearing, scheduled for August 6 but likely to be delayed.

John Pike, the lawyer representing the US government, says they only need to prove there is a case to answer in the extradition hearing as he was not being tried in New Zealand.

Dotcom could only challenge whether the evidence the government produced was manifestly unreliable, Mr Pike told Chief Justice Helen Winkelmann at a hearing in the High Court in Auckland on Wednesday.

But Dotcom's lawyer Paul Davison said it would be nonsense to not allow him to question the evidence.

Mr Davison said Dotcom couldn't be extradited without a fair process, which means the US must establish reasonable grounds to conclude he may have committed the offence.

He said it was wrong for the prosecution's documents to be presumed to be reliable without a proper questioning.

"That's lip service to the judicial process, and in my submission the law requires much more than that."

Justice Winkelmann reserved her decision, APNZ reported.

Meanwhile, Dotcom told the Torrent Freak website that he believed US Vice President Joe Biden was instrumental in his arrest and the closing of Megaupload.

He said outside court on Wednesday that the role of Hollywood interests in the case was significant.

"Hollywood has placed their own people inside the Department of Justice. Hollywood is one of the most significant contributors to the campaign of Obama and his re-election.

"When you look at all of this I think this is really a very commercial interest for the United States and they are trying to defend an outdated business model."