Kim Dotcom may have to wait until next year to find out if he will be extradited to the United States - more than two years after his initial arrest in January 2012.
The FBI is trying to extradite the internet entrepreneur to face charges of internet copyright fraud, racketeering and money laundering.
His extradition hearing has already been delayed several times due to legal action relating to an illegal raid on his home in January 2012 and disclosure of evidence relating to his case.
Mr Dotcom's lawyers have been arguing they need to see the evidence the Crown and the FBI have against their client, so they can properly prepare for his extradition hearing.
The District and High Courts ruled in their favour, but the Court of Appeal overruled them.
The case will now be heard at the Supreme Court on 30 July.
A hearing in August has now been put off until April 2014. But a tentative date has been set for November, just in case a final ruling on whether the lawyers should have access to evidence is quickly made.