The judge overseeing the Kim Dotcom extradition case has stepped down after making comments suggesting the United States was the "enemy".
Judge David Harvey surrendered his role in the case after making comments during a copyright discussion at an internet conference.
An internet law expert, Judge Harvey had been considered the perfect choice to hear arguments on whether Dotcom and his Megaupload colleagues should be extradited by the United States to face charges of criminal copyright violation.
The district court's chief judge Jan-Marie Doogue said Judge Harvey had made the decision to step down from hearing the case.
"He recognises that remarks made in the context of a paper he delivered on copyright law at a recent internet conference could reflect on his impartiality and that the appropriate response is for him to step down from the case."
Judge Harvey made the comments at NetHui during a conference discussion on copyright and trade talks with the US. He referred to a tweet which had played on a reference to cartoonist Walt Kelly: "We have met the enemy and he is [the] U.S."
The case, scheduled for March, would now be heard by Judge Nevin Dawson. Judge Dawson has previously heard elements of the case including making the decision to allow the internet giant bail in February after a month in jail.
The case has been bruising since the outset with the judge initially hearing it reprimanded for treatment of media.
It has also seen criticism of the Crown Law Office and the police. The wrong type of restraining order was initially used to seize the cash and assets of the accused. Then the search warrants were ruled invalid because they were too broad, making the search and seizure illegal. It also emerged the FBI had taken evidence back to the US without the knowledge of the police and Crown - and now want to use it to help extradite the Megaupload accused.
Auckland university associate professor Bill Hodge said the case involved new technology arguments in an "antiquated" legal framework argued by talented lawyers. "It is uniquely high stakes."
He said it was the "case of a lifetime" for Judge Harvey. "He is recognised as one of New Zealand's experts - not just as a judge but as an expert who has gone into copyright issues."
A high court hearing next month will hear evidence of the January raid during which Dotcom, Finn Batato, Mathias Ortmann and Bram van der Kolk were arrested. The FBI has accused Dotcom and others working at Megaupload website of the world's biggest case of criminal copyright violation.