Lotto officials are still searching for two of the Powerball players who won $7.18 million on the weekend.
The $50 million jackpot was won by seven people, most were from Auckland, with one from Hamilton and another from Hastings.
Lotto NZ's Lucy Fullerton said two people who purchased tickets in Auckland had yet to come forward.
The tickets were bought at Woolworths Metro on Victoria Street and at Royal Oak Mall.
She told First Up they had ways of tracking the winners down.
"With a big prize like this, any Powerball prize, we'd give it two weeks and then we'd probably start taking steps to try and find the winner.
"There are a whole range of ways and obviously we have to be careful about people's privacy and so we have a very strict well-defined process for how we can look for people, I can't share everything about it because...we don't want copycats."
Lotto NZ knew the date and time the tickets were purchased and could gather information from CCTV or EFTPOS transactions.
Fullerton said it was unusual that all the winners had not yet come forward, though it had been less than a week.
People had 12 months to claim a prize, though most PowerBall winners claimed within three days, she said.
A PowerBall prize had never gone unclaimed..
RNZ