Internet entrepreneur Kim Dotcom lost a ruling in New Zealand’s highest court on Friday as part of his legal battle to try and avoid extradition to the United States.

Dotcom founded the once-popular file-sharing site Megaupload, which US prosecutors shut down in 2012. Prosecutors accuse him and colleagues of racketeering by facilitating the widespread illegal downloading of songs and movies. Dotcom argues he can’t be held responsible for those who chose to use his site for illegitimate purposes.

In a 4-1 ruling, New Zealand’s supreme court denied a bid by Dotcom and three of his colleagues, who are also facing extradition, to have access to all the US evidence against them at their July extradition hearing. Chief Justice Sian Ellias cast the dissenting vote.

The court agreed with a previous ruling that extensive disclosure could bog down the process and a summary of the US case would suffice. The court found the country’s extradition act does not require foreign countries to provide such disclosure.

While the ruling effectively ended one legal argument for Dotcom, the supreme court may end up ruling on other aspects of the case.

Last year, Dotcom launched a new site called Mega. He’s also said he plans to launch a political party to contest New Zealand’s general elections in September. Since his 2012 arrest and subsequent release, Dotcom has been a colourful figure in New Zealand’s political and media scene.

He reacted to the decision on Twitter on Friday.

“It’s disappointing that we lost in the supreme court by majority decision. But great that Chief Justice of NZ would have allowed our appeal,” he wrote in one tweet.

“Being defeated is often a temporary condition. Giving up is what makes it permanent,” he wrote in another.