Almost $800,000 has been spent on security guards since containers from the stricken MV Rena began washing up on Bay of Plenty beaches.
Guards have been stationed around the clock on beaches across the region since the operation began in October.
But Maritime NZ is refusing to reveal details of how the $37 million clean-up bill has been spent, for fear it could jeopardise their chances of recouping money from the ship's owners.
Information obtained under an Official Information Act request shows the cost of security, and reveals that a further $30,000 has been spent choppering food to a marae on Motiti Island to feed the response team's volunteers and staff.
Harry Hawthorn, general manager of the Rena response group, declined to detail the costs any further.