The Mayor's office says Auckland Transport paid for security guards at an event Len Brown and a few protesters were at.
During the opening of a new transport station in Panmure on Saturday Mr Brown was flanked by a security guard and guards were placed around the marquee he spoke in.
A councillor says ratepayers should be concerned by the number of security guards being used at events attended by Len Brown.
Orakei councillor Cameron Brewer says ratepayers need to be assured they are not paying for guards to protect the mayor from peaceful demonstrators protesting against his personal actions. He says ratepayers should not be paying for guards to protect the mayor while he battles personal issues.
"The fact is that wherever this man goes there's always going to be a few hecklers, a few peaceful demonstrators and that's no justification for bringing in the heavies and putting them on the public payroll."
Mr Brewer says the guards would be justified if a genuine risk or threat had been directed at Mr Brown.
A spokesperson for the Mayor's office has confirmed the guards at Saturday's event were paid for by Auckland Transport - a division of the council.
He says the Mayoral office does not have a security budget and would not expect anything more than normal arrangements to be provided at events.
Two protesters at the event voiced their opinions on Mr Brown's use of free or upgraded hotel rooms, and on his extra-marital affair.