"The reconciling of total costs and breakdown of expenditure is relevant to recovery of costs from the shipowner. To make that information available in its raw data could prejudice the economic interests of New Zealand."
The costs include spending on accommodation, boats, cars, contractors, cranes, equipment and flights. Additional money went towards health and safety equipment, spill control, waste disposal and efforts to save wildlife.
Maritime New Zealand will try to recoup the $37 million from the ship's Greek owners Costamare Shipping, whose subsidiary Daina Shipping Company is due to appear in court on July 18.
Meanwhile, the Phillipines embassy has thanked New Zealand authorities for their "humane and fair" treatment of the jailed seamen.
Captain Mauro Balomaga, 44, and navigator Leonil Relon, 37, were sentenced in Tauranga District Court on Friday to seven months in jail after they were found responsible for running the ship aground on the Astrolabe Reef off Tauranga's coast on October 5. Balomaga also faced a charge of altering ship documents.
The embassy said it appreciated the "understanding and concern of the local communities during this difficult period".