A $100 million Powerball prize is still unclaimed a week after the winning ticket was announced, prompting lottery officials to urge gamblers to register their tickets.

A single Sydney ticket scooped the entire $100 million jackpot last Thursday, June 12.

The winning entry was bought at Bondi Junction Newsagency and Internet Cafe, 191-195 Oxford Street, Bondi Junction.

But so far, nobody has come forward to claim the prize.

The Lott spokesperson Khat McIntyre said the elusive winner could already have been alerted to their good fortune if they had registered their ticket to The Lott Members Club.

"It's the question many Aussies have been asking during the past seven days: who won last week's $100 million Powerball prize, and do they know they've won?" she said.

"By registering your in-store or online lottery entry to The Lott Members Club, not only are we able to contact you straight after the draw if you win big, but your prize is secure."

Even if a registered ticket is lost or damaged, she said, the holder could still get their prize.

She urged people to ask their retailer about registering, or to do so online.

While players in NSW have six years to claim their prizes, McIntyre said The Lott was keen to speak to the winner and start the prize claim process as soon as possible.

"We pay division one prizes two weeks after the draw, so this prize is ready to be put into someone's bank account in a week's time – on Friday 27 June 2025," she said.

"The first step is to give us a call on 131 868 if you think you are holding the division one winning entry."

The winning numbers in last Thursday's draw were 28, 10, 3, 16, 31, 14, and 21, with a Powerball number of 6.

There are many different ways to get help and information about gambling. You can visit the National Gambling Helpline or call on 1800 858 858.