Embattled Megaupload founder Kim Dotcom has lost the latest round of his legal fight against extradition to the United States, after a New Zealand court ruled that the US does not have to grant him access to key evidence in the case ahead of the main hearing in August.

According to the court, the main purpose of the extradition hearing is for the US to demonstrate it has a valid case against Dotcom, not to prove his guilt or innocence. Hence, a full disclosure of evidence is unnecessary, and would only slow down the legal process.

“Even though courts play a vital part in the process, extradition is very much a government to government process,” explained the court.

“It is for the requesting state to decide what information it wishes to put before the requested state in support of its request.”

The ruling comes as a blow to Dotcom as he needs access to the evidence in order to prove to the court that the US has no case against him. As it stands now, he won’t see what the US’s argument against him is until the full hearing, making it much more difficult to claim that he should be allowed to remain in New Zealand.

But Dotcom hasn’t given up the fight yet, taking to Twitter to quickly announce his intention to appeal the latest ruling:

The decision came after the US appealed against two earlier rulings by lower courts that it should provide the Megaupload founder with all the evidence it was basing its case on. New Zealand’s Supreme Court is now the last avenue of appeal for Dotcom, who will first have to submit application to do so before judges decide if there is enough merit for a full appeal. Should the request be granted, it could well be that Dotcom’s extradition hearing will be further delayed. It’s already been postponed once, having originally been pencilled in for this March, and any further appeal would almost certainly cause further delays.

The case has been dragging on ever since January 2012, when more than 70 uniformed officers stormed his New Zealand mansion at the request of the US Department of Justice at the same time that authorities took Megaupload offline. Dotcom is officially wanted in the US on charges of facilitating copyright fraud due to his involvement with Megaupload.

Dotcom refutes these allegations, saying that he is not responsible for the actions of those who used his service to illegaly download pirated content. In addition, Dotcom says that he is the victim of a smear campaign by the US.

Pending the outcome of the case, Dotcom has been allowed out on bail, during which time he has already launched the successor to Megaupload – a new file sharing service called Mega. Just like Megaupload, Mega allows users to upload and share large files online, with the key difference being that Mega offers extensive security features to protect the privacy of its user’s files.