The Crown will appeal against the High Court ruling that search warrants used in the Kim Dotcom case were illegal, it has been reported.

Chief High Court Justice Winkelmann ruled last month that search warrants use to enter Dotcom's mansion in Coatesville north of Auckland were too broad.

The Crown confirmed today it would take the case to the Court of Appeal, Radio New Zealand reported.

Justice Winkelmann found that the search warrants used in the raid in January, issued by the District Court, were invalid because they did not adequately describe the allegations against the internet millionaire.


She said the warrants, issued by the District Court, gave police authority to seize too wide a range of items.

Dotcom and Finn Batato, Mathias Ortmann and Bram van der Kolk were arrested in January after a request for assistance from the FBI.

The United States claimed the men were behind the world's biggest criminal copyright violation through Dotcom's filesharing website Megaupload, which carried about 4 per cent of the world's internet traffic. The men deny the charges.