Auckland Council is estimating the Occupy Aotea protest could cost ratepayers up to $200,000.
The group have been camping in Aotea Square for the past five weeks as part of a global protest movement.
Auckland Council has formally asked the protesters to leave the site and is threatening trespass notices if they ignore the request.
However police may not enforce such a trespass notice, due to Bill of Rights implications which they cited as a reason not to move protesters in Dunedin on.
Auckland Council said it has lost $8000 in revenue from cancelled events because of the occupation, has spent $20,000 a week on security guards, $500 a week on wire fences around the site, and another $60,000 will need to be spent on inspections of any potential damage caused to the waterproofing of the underground parking from tent pegs, Radio New Zealand reports.