About 50 residential brothels in the central Auckland area have been raided in the past year after 95 complaints were made to the Auckland Council.
Council resource consents manager David Oakhill said the complaints related mainly to breaches of district plan rules, such as brothels operating in residential areas.
"A number of these complaints were found to be well-founded and we took appropriate action, either to close the operation or ask the operator to formalise the activity through resource consent," said Mr Oakhill.
He said police were called during six of the raids after the operators refused to let council officers on to their properties.
"When investigating complaints of this nature, council officers visit the premise to ascertain whether the complaint is legitimate, and sometimes search warrants are required."