A lawyer for Kim Dotcom says his client is very frustrated that his extradition hearing in New Zealand has been delayed until next year.
United States authorities are seeking to extradite the founder of the file-sharing website Megaupload to face charges relating to a major internet copyright prosecution.
The North Shore District Court judge who will preside over the extradition case and lawyers for both sides have agreed to postpone the hearing, due to outstanding proceedings at the Auckland High Court.
Mr Dotcom, a German national with New Zealand residency, was due to have his case heard in early August.
However, the parties have agreed to put that off until March 2013 to allow appeals against rulings regarding the legality of search warrants and the disclosure of evidence to be heard.
In a tweet on Tuesday, Mr Dotcom accused US authorities of playing dirty delay tactics.
His American lawyer Ira Rothken agrees with that, saying American authorities are appealing against New Zealand judicial rulings that would entitle Mr Dotcom to a fair trial.
"He's under the cloud of allegations - notwithstanding the fact that he's innocent until proven guilty. His assets are frozen and it is a very stressful and hard time for his family. So to remove that cloud is very important and the delay is very frustrating."
Mr Rothken told Radio New Zealand's Checkpoint programme on Tuesday the legal team want copies of evidence the FBI plans to use against Kim Dotcom so they can properly defend him at the hearing.
However, the FBI is refusing to hand anything over and is appealing against a New Zealand judicial ruling which said it had to.
A New Zealand-based lawyer for Mr Dotcom, Willy Akel, says the three-week extradition hearing is tentatively scheduled for 25 March.
Megaupload was indicted in a US federal court in Virginia on 19 January this year and the site was shut down. Mr Dotcom and three co-accused were arrested in Auckland the following day.
Formal papers requesting their extradition were lodged by the US in March.