The ticket bought online was the only division one entry, The Lott officials said.
Multiple phone calls have been unable to reach the mystery new millionaire.
“I was ready to confirm Powerball’s newest division one winner straight after the results of tonight’s draw were known, but sadly whenever I called the number provided, it just rang out and went straight to message bank,” The Lott spokesperson Matt Hart said.
“If you see a number of missed calls on your phone, you could be the winner we’re trying to contact.
“You may not think it’s possible you’re the division one winner we’re searching for, but if you purchased an online entry into this week’s Powerball draw that you haven’t checked yet, you’re in with a chance.”
The new millionaire is the seventh Powerball division one winner of 2021. Five of those seven wins have been in New South Wales.
In 2020, 14 Powerball division one winners across Australia pocketed more than $470.1 million in prize money.
Powerball twice offered an $80 million jackpot last year, the biggest prize offered by any Australian lottery game during the year.
Of the 14 Powerball division one winning entries in 2020, six were in Queensland, five in New South Wales and three in Victoria.