Ira Rothken, Dotcom's lawyer, said they are disappointed by the judgment from the New Zealand Court of Appeal.
Internet mogul Kim Dotcom has lost another fight in his epic legal battle to avoid being extradited to the United States.
Instead, a panel of three judges backed the FBI-led case, which has dragged on for more than six years.
US authorities claim that Dotcom and his associates, who are also being charged, cost American recording and film companies hundreds of millions of dollars through online piracy on Megaupload. If handed over to the U.S., he and his three co-defendants will face charges of copyright infringement and fraud that resulted in damages to record and film studios to the tune of over $500 million. He was arrested soon after by New Zealand police who descended on his luxury mansion in Auckland in two marked helicopters, and had to cut their way into a locked safe room to reach him.
"We have now been to three courts each with a different legal analysis", Mr Rothken wrote on Twitter. Dotcom had built a massively successful company called Megaupload that had become a popular platform for illicit sharing of copyrighted movies. Dotcom and his co-accused have always maintained their innocence.
"We look forward to seeking review with the New Zealand Supreme Court".
"I'm an easy target, they needed a villain who's rich, flamboyant and over-the-top like me", he said in 2013, claiming U.S. prosecutors were chasing him at the behest of Hollywood studios.
Despite his third failure in the New Zealand courts, Dotcom seems to be confident that the Supreme Court, the court of last resort in his case, will take his side.
The Court of Appeal released its finding today, upholding the decision of the High Court and District Court.
Now, the final decision as to whether the Dotcom and the other men will be extradited rests with Justice Minister Andrew Little.
The group can seek leave to appeal the Court of Appeal's judgement to the Supreme Court.
He launched a multi-billion dollar damages claim against the New Zealand government this year, saying it had destroyed his business and damaged his reputation.