Kim Dotcom's content sharing Megaupload empire might not keep the same moniker but will be back in some form or another if the US government's case fails.

The US government's bid to extradite the internet tycoon and co-accused Finn Batato, Mathias Ortmann and Bram van der Kolk went to the Court of Appeal in Wellington today, with the USA seeking to quash court orders granting Dotcom's team access to evidence ahead of the extradition hearing. The court reserved its decision.

Speaking to reporters after today's hearing, Dotcom said the US government's case was "very malicious" and if it fails, he will be back after the US authorities shut down his content sharing empire. .

"Megaupload might not bounce back in its own form, but there will be a new mega at some point," Dotcom said.

"This is a very political case, because it's actually the US government trying to defend an outdated business model by a handful of billionaires that are shareholders in these large content producing companies. They are trying to use this case to basically change the way the internet works," he said.

The US government alleges Dotcom and his co-accused engaged in criminal copyright infringement and money laundering of more than US$500 million.

Dotcom says his legal team told him he was "operating within the boundaries of the law," and he is surprised other content sharing sites, such as Youtube, "that contain much more infringing material than mega ever had in its history" haven't been chased.

"The thing I'm nervous about is the ongoing delaying tactics by the US utilising Crown law to appeal every time we win in court and just dragging things out," Dotcom said.

"If it was up to them, we would have no money for our legal defence, no evidence to defend ourselves, we would not even have our own computers back to show our own evidence."

Paul McBeth