Kim Dotcom's lawyers have accused the FBI of an "illegal act'' after it emerged agents had left the country with cloned copies of computers seized during raids.
William Akel told the High Court at Auckland today that there were written agreements with government lawyers which meant the computers were meant to be kept under police guard.
The court has been told 18 hard drives were copied and taken to the US by FBI agents working in the NZ Police electronic crime lab.
The drives were seized during the January police raids which saw Dotcom and three colleagues arrested on US charges of criminal copyright violation.
Dotcom, Finn Batato, Mathias Ortmann and Bram van der Kolk had gone to court ahead of their August 6 extradition hearing to argue that the search warrant used by police was too broad.
It emerged last week that data had already been taken to the US even though Dotcom's lawyers say they had agreed nothing would happen before a court hearing on the issue.
High Court Chief Judge Helen Winkelmann ordered the Crown to return today with an explanation as to why the FBI had already removed data from New Zealand.
Mr Akel said the paper trail provided by the Crown acting for the Attorney-General showed it had breached an agreement with Dotcom.
He said it was possible Crown Law had been kept in the dark and it had been "gazumped'' by the FBI ahead of the proper court hearing.
"If they went offshore without a directive from the Attorney-General then it is an illegal act,'' he said.
The Crown has yet to respond but has indicated it had granted the FBI permission to remove the clones and that Dotcom's lawyers would have been aware it was being done.
At an earlier stage in the hearing, the Crown had said complying with a disclosure order from the District Court created so much work it was likely to be months before it was complete.
Doing so would push the extradition hearing beyond its current August 6 schedule.By David Fisher @@DFisherJourno Email David