New Zealand's Supreme Court found the U.S. does not have to provide full documents in its extradition bid

U.S. prosecutors do not have to provide defendants in a high-profile criminal copyright case full copies of documents it references in its extradition request, New Zealand's Supreme Court ruled Friday.

The U.S. is seeking extradition of Kim Dotcom and three of his colleagues who ran Megaupload, a file-sharing site prosecutors allege unfairly profited by allowing its users to trade content it knew was subject to copyright protection.

A District Court granted Megaupload's request to see such evidence, a ruling that was upheld by the High Court. The Court of Appeal then reversed the decision, and Megaupload appealed to the Supreme Court.

"It's disappointing that we lost in the Supreme Court by majority decision," Dotcom wrote on Twitter. "But great that Chief Justice of NZ would have allowed our appeal."

In order to make an extradition request, the U.S. provides a summary of evidence used to establish a prima facie case that is used to determine eligibility for extradition, according to a news release from the Supreme Court.

In a 4-1 decision, the Supreme Court panel found that requirement does not mean the U.S. must provide "copies of all documents it summarizes."

The U.S., however, is bound to disclose information "that would render worthless or seriously undermine the evidence upon which it relies," the court's news release said.

The ruling could prove a setback for Dotcom and Megaupload, whose legal team may now have less ground to challenge extradition.

Dotcom along with Finn Batato, Mathias Ortmann and Bram van der Kolk were indicted in January 2012 in U.S. District Court for the Eastern District of Virginia on charges of criminal copyright infringement, money laundering, racketeering and wire fraud.

U.S. prosecutors allege Megaupload encouraged its users to share content that is copyright protected and netted US$175 million in criminal proceeds. Megaupload contends it removed content when requested and did not sanction copyright infringement.