There's a new millionaire walking around who doesn't yet know it.
The hunt is on for a mystery person who purchased the winning Monday Lotto ticket from a Warrawong newsagency.
NSW Lotteries officials have no way of notifying the division-one winner as the ticket wasn't registered.
The $1 million winning ticket was purchased from King Street Newsagency, Shops 4C, 145 King Street in Warrawong.
The winning numbers in Monday Lotto, draw 3211, on December 14 last year were 3, 28, 5, 21, 12 and 6 with the supplementary numbers 18 and 32.
NSW Lotteries spokesperson Zoe Knobel said that anyone who thinks they may have the winning ticket should contact NSW Lotteries as soon as possible.