Officers who led police raids on Kim Dotcom's mansion may take the stand to give evidence as part of a judicial review of the searches.

The warrants that authorised the searches, carried out in January by New Zealand police on behalf of the FBI, were deemed illegal in a judgement delivered last week by High Court judge Helen Winkelmann.

Kim Dotcom ... wants all irrelevant material seized in the raids to be returned.

She also ruled it was unlawful for copies of Dotcom's computer data to be taken offshore.

Lawyers for Dotcom and the Crown must now decide how to resolve the dispute, with Dotcom seeking an independent lawyer to go through the seized evidence and return all irrelevant material to him.