The $17.1 million winnings from a Lotto ticket purchased in Twizel remains unclaimed.
"We haven't heard from the lucky winner yet," Lotto NZ spokeswoman Marie Winfield told the Herald on Thursday morning.
Winners have 12 months to claim their winnings but Winfield indicated Lotto NZ would make every effort to find the person with a win of this size.
The multi-million dollar winning Powerball first division ticket was purchased at The Market Store in Twizel.
A few years ago, Lotto managed to track down a Powerball winner who did not claim the winnings through CCTV footage.