Mr Jones said it was not uncommon for unelected people to sit on and lead local government audit and risk committees, and the Office of the Auditor General recommended it.
"The role of the independent is to provide independent advice and leadership to the committee, independent of management and the elected members," he said.
He had similar roles at six other councils. He worked a day and half per month at most for HDC.
Mr Jones has previously been an auditor and was chief financial officer at Western Bay of Plenty District Council for 14 years.
Deputy Mayor Wayne Bishop said most councillors knew Mr Jones though Local Government NZ workshops and were more than comfortable having him as committee chair.