Kim Dotcom can be extradited to US but can also appeal

Kim Dotcom denies all the charges

A long-running effort to extradite file-sharing site mogul Kim Dotcom to the US has been left in limbo after a Supreme Court decision in New Zealand.

The court ruled that he can be returned to the US to face copyright charges - but has also overturned another lower court's decision, effectively granting him the right to appeal.

Mr Dotcom himself described the ruling as a "mixed bag".

The legal wrangling is likely to continue.

The court ruled that Kim Dotcom and his three co-accused were liable for extradition on 12 of the 13 counts the FBI is seeking to charge them with.

But it also ruled that the Court of Appeal had erred in dismissing judicial review requests from Mr Dotcom, and granted him the right to continue with them.

The FBI alleges that Megaupload facilitated copyright infringement on a huge scale, but Mr Dotcom's lawyers argue that the website was never meant to encourage copyright breaches.

If he is extradited, he faces a lengthy jail term.

Controversial figure

In response to the ruling, he tweeted a statement from his lawyers which read: "For the Dotcom team, and especially for Kim and his family, it is a mixed bag."

"There is no final determination that he is to go to the United States. However, the court has not accepted our important copyright argument and in our view has made significant determinations that will have an immediate and chilling impact on the internet."

The controversial figure founded file-sharing site Megaupload in 2005, and made millions of dollars from advertising and premium subscriptions.

At one point, he boasted that it was responsible for 4% of internet traffic.

In 2012, he was arrested when armed police stormed his Auckland home in a dramatic dawn raid, which was later to become the subject of its own legal enquiry, when Mr Dotcom sued for damages.

A district court in New Zealand ruled in 2015 that he could be extradited, but a series of appeals and judicial reviews followed.

Lawyers for Mr Dotcom argued that his actions did not amount to criminal offences in New Zealand, and were therefore not extraditable.