United States officials had trawled through 14 million emails from the devices.
The selection of documents they had chosen in their case against Dotcom were misleading and did not show his business Megaupload in context, Mr Davison said.
"Mr Dotcom has been assiduously trying to get this material since shortly after it was taken from him."
Some of the information was encrypted, but Mr Davison said his client was happy to provide to police the code, but it was stored on a computer that he did not have access to.
The delay in getting the information to Dotcom before next year's trial was prejudicial against him, Mr Davison said.
"This is just going to get worse and worse and the prejudice will only get more extreme."
Mr Foley, who appeared for van der Kolk agreed with Mr Davison's submissions.
It was "quite wrong" that his client should appear for a criminal hearing without having access to all the information.
David Boldt, for the Crown said it was a "slur" by Mr Davison to imply the delay in returning the data was part of a conspiracy.
The only reason Dotcom's data had not been sent to him was because he had not provided a code for information that was encrypted.
The Crown was happy to return the "cloned" information to the respondents and the original devices would be sent to the United States, he said.
Justices Ellen France, Tony Randerson and Douglas White adjourned the hearing for a few hours to see if the lawyers could agree to a manner in which the information could be delivered to Dotcom and his co-accused.
