A New Zealand judge has ruled that the search warrants against Megaupload founder Kim Dotcom were invalid, and that data shouldn't have been handed to the FBI.
File-sharing site Megaupload was shut down in January by the US Department of Justice, which described it as an 'international organized criminal enterprise' and is seeking Dotcom's extradition.
Dotcom was arrested along with four other people and charged with racketeering, money laundering and copyright offenses, and had millions of dollars worth of assets seized or frozen.
But in a ruling with serious implications for the future of the case, High Court judge Justice Helen Winkelmann has ruled that because the warrants were general in nature, they were invalid.
"The warrants did not adequately describe the offences to which they related," she said. "They were general warrants, and as such, are invalid."
She also ruled that it was unlawful for the data and hard drives seized in the raid to have been sent abroad.
"The release of the cloned hard drives to the FBI for shipping to the United States was contrary to the 16 February direction that the items seized were to remain in the custody and control of the Commissioner of Police," she ruled.
She said that the raids could have amounted to unreasonable search and seizure, and may even have constituted trespass.
Dotcom has already successfully argued for the return of some of his assets, and that he should be given bail. Tomorrow, in a Virginia federal court, Megaupload's lawyers are expected to call for the charges to be dropped altogether.
Meanwhile, Dotcom has won the support of another influential figure: Apple co-founder Steve Wozniak. In an interview with the Associated Press, he described the charges as 'hokey', and said the case was a threat to the freedom of the internet.