US prosecutors have won a court case that brings them a step closer in their attempts to have the Megaupload founder and three of his colleagues extradited from New Zealand.

The appeals court in Wellington overturned an earlier ruling that would have allowed Kim Dotcom and the others broad access to evidence in the case against them at the time of their extradition hearing, which is scheduled for August. The four are accused of facilitating massive copyright fraud through the internet filesharing site.