The FBI is accused of “illegally” copying evidence used in a case against file-sharing site Megaupload.

Megaupload was shut down in January and its operators arrested in New Zealand because, alleged the FBI, it was being used to pirate content.

Lawyers acting for Megaupload said the FBI had illegally removed hard drives containing evidence.

NZ government lawyers said the removal was legal because the relevant law only covered “physical” items.

Megaupload lawyers leveled the accusation at the FBI in an Auckland court saying the FBI had broken written agreements covering what could be done to digital evidence.

The FBI is accused of "illegally" copying evidence used in a case against file-sharing site Megaupload

New Zealand police seized seven hard drives during raids on Megaupload when the site was shut down. The written agreements said the drives should not be handed to US investigators prior to a hearing to decide how they were to be treated.

However, Megaupload lawyers say that FBI agents copied the drives and took the cloned information back to the US before the hearing took place.

If the copying and removal was done without the consent of the New Zealand authorities it would constitute an “illegal act”, said Megaupload lawyers.

The New Zealand authorities were summoned to court to explain how the FBI was allowed to remove the data from the country.

The government’s legal head said the agreement the FBI was accused of breaking did not apply in this case. He said the relevant document only covered “physical” material not information.

The trial of Megaupload founder Kim Dotcom and the site’s management team is due to start on 6 August.