The Maori Council's legal team says it's responding to new Crown evidence presented to the Waitangi Tribunal hearing into water rights.
Although the tribunal is no longer sitting in public, council lawyers are sifting through hundreds of pages of written submissions.
Lead lawyer for the claimants, Felix Geiringer, says the deadline for replying to the inquiry in writing is Wednesday.
The tribunal's next step will be to make a recommendation responding to the claimants' call for the Crown to delay the sale of shares in Mighty River Power.
The inquiry will then compile a report on all the evidence presented so far.
A second round of hearings into water rights and interests will be held before a full tribunal report is drawn up.