German tech entrepreneur Kim Dotcom has lost a bid to block his extradition from New Zealand to the United States to face charges including copyright infringement and money laundering.
The ruling is a major victory for the US Department of Justice in the long-running case, and comes almost four years after police raided Dotcom's mansion west of Auckland at the behest of the FBI and shut down his popular file-sharing website, Megaupload.
"I'm disappointed," Dotcom told reporters as he left the court, promising to fight the ruling.
US authorities say Dotcom and three co-accused Megaupload executives cost film studios and record companies more than US$500 million and generated more than US$175 million in profits by encouraging paying users to store and share copyrighted material, such as movies and TV shows.
The New Zealand prosecution, which argued the case for the US. government, said Dotcom and his executives had encouraged and paid users to upload pirated films and music to generate profit.
Lawyers for Dotcom argued the evidence for this was thin. They said Megaupload was an internet service provider similar to services such as Dropbox, and protected by copyright law from liability for users' uploading pirated files.
Judge Nevin Dawson ruled the prosecution had established a case for all four defendants to answer.
"We plan to appeal. We think the judge was wrong on the law," Dotcom's lawyer Ira Rothken said.
"Justice wasn't done today."
New Zealand's justice minister will make a final decision on whether Dotcom will be handed over to the United States.
Dozens of black-clad police raided Dotcom's mansion in 2012, breaking him out of a safe room and confiscating millions of dollars in cash and property, including a fleet of luxury cars, computers and art work.
Years of legal wrangling ensued and it emerged that New Zealand's Government Communications Security Bureau had illegally spied on Dotcom before the raid.
Dotcom maintained a high profile while fighting his case, setting up a political party and new companies and taunting both the New Zealand and US governments.
The case has been watched closely by the media industry and developers in the file-sharing business for signs of how far Washington is willing to go to protect US copyright holders.
Being able to extradite possible copyright-breachers to face charges in the United States would avoid the risk of file-sharing websites operating out of foreign safe havens, according to legal experts.