Outgoing Papakura Mayor Calum Penrose hopes a Papakura person is the winner of Saturday night's Lotto prize, worth $28,710,403.
The winning ticket was sold at a Mobil station there.
The amount comprises both the Powerball win and $400,521 from Lotto first division.
Mr Penrose also hopes some of the money can be put into the community.
He says that if a local person has won the prize, Papakura's size means it will not stay a secret for long.
The Lotteries Commission says it's not yet known if an individual or a syndicate won the prize.
Powerball jackpotted for 16 weeks before Saturday night. It's only the second time a jackpot has continued that length of time.
The Lotteries Commission says the win eclipses the previous biggest Powerball prize of $22.4 million.
That prize was won last year in Manukau.