Thursday's loss has become the third in line for Internet entrepreneur Dotcom. Earlier, his appeal was rejected consecutively by New Zealand's North Shore District Court and the High Court.

In its ruling on Thursday, the Court of Appeal argued that the US case was warranted, as it relied on "available extradition pathways" propped up by "sufficient evidence."

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A German national, Dotcom, founder of the now-defunct Megaupload filesharing website, has been fighting his extradition since his arrest at his Auckland home in 2012. If handed over to the US, 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.

Dotcom has slammed the decision, arguing that "the Court's interpretation of the relevant copyright provisions cannot be right" and it creates a dangerous precedent that would make Internet providers criminally liable "for the misuse of their services by users, as it claimed against me."

Dotcom was "extremely disappointed" by the court's stance, and, without mincing words, he dismissed it as being "in complete denial of the legislative history and intention of the Copyright Act."

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"Therefore it has the value of toilet paper," he tweeted.

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.

"Time for the Supreme legal minds to sort this mess," he stated.