The long-running legal battle involving Kim Dotcom has been left unresolved by a Supreme Court ruling issued today.
While today's ruling paves the way for extradition, it is subject to a judicial review.
The Supreme Court also found the men were not eligible for extradition on the conspiracy to commit money laundering charge, but were on another 12 charges.
Since their arrests in 2012, Dotcom, Matias Ortmann, Bram van de Kolk and Finn Batato have been fighting extradition to the United States.
The authorities there say they profited from encouraging people to breach copyright by uploading files like music and movies from their MegaUpload website.
When a district court gave the go-ahead for extradition in 2015, the group challenged that with a judicial review.
The High Court and Court of Appeal dismissed the review but the Supreme Court now says it must go ahead.
The grounds for that review include procedural unfairness, breach of natural justice, errors of fact and unreasonableness.
The Supreme Court found that the Court of Appeal erred in concluding that the judicial review proceedings were an abuse of process.
It says instead the court should have looked at whether the grounds for the review had been considered by the lower courts.
The court has asked the parties to file brief submissions on the issues that remain outstanding in the judicial review proceedings and for their view on which court these issues should be resolved in.
Dotcom's lawyer Ron Mansfield described the Supreme Court's ruling as a mixed bag, saying there were some wins and some losses in the judgment.
Mansfield said the court had correctly accepted that they should be able to argue against what he called "serious procedural issues" that had arisen in the case.
He said these issues stem from the supply of information they had been able to get from the United States and New Zealand authorities. There has also been restrictions on the way Dotcom's legal team can fund a defence, because of the way authorities have applied the proceeds of crime laws.
The United States had taken action to prevent his client accessing funds, he said, meaning he has had the money to fund lawyers, but not experts.
Mansfield said this meant there would be further argument in the Court of Appeal and the Supreme Court regarding what he described as significant concerns that were well established in evidence.
He said the court had not accepted their argument on copyright, which he said would have far reaching ramifications for the internet both in New Zealand and offshore.
"That will have an immediate and chilling impact on the internet," he said.
"That's because Internet Service Providers (ISPs) can be found criminally liable, effectively, for the acts of its users, certainly if they're aware that its users are infringing copyright. You don't have to look very far on most websites to see copyright infringement. So it extends civil liability, which we all knew existed in New Zealand, into criminal liability."
Mansfield said the legal team was also waiting to see how the internet communities in New Zealand and overseas reacted and responded to today's judgment.
He said it would be interesting to see how the challenges faced by ISPs were responded to.
"Can we live with it? Will it result in access restrictions and further costs that we will incur as a result? Or will our government be lobbied to intervene and provide real and workable protections for them? With Covid-19 upon us, access to the internet is now essential to our business community, more so than it has ever been in the past."
A final decision as to whether the men are eligible for surrender will be made once the judicial appeals are resolved.