It's time to check your wallet, turn out your drawers and dig through that glove box, there's a $6.5 million winning Powerball ticket on the loose in Gisborne.

A ticket bought at Grant Bros in Gisborne won $6.5 million with Powerball on Saturday, but Lotto New Zealand is still waiting for the lucky winner to claim the prize.

The $6.5 million win is the third Powerball First Division prize won in the area since the game began and the largest prize ever won by a Gisborne player.

"While some winners are quick to check their tickets, it's not unheard of for big winners to wait a couple of days to claim their prize," said Emilia Mazur, Lotto NZ general manager corporate communications.

"Sometimes people want to take a bit of time to let the win sink in or arrange time off work before they come and collect their winnings or they may not even know yet that the little yellow ticket they have tucked away somewhere is worth $6.5 million."

With a winning Powerball ticket hiding somewhere in the city, Lotto NZ is urging Gisborne Lotto players to dig out their tickets and get checking.

"Most big winners keep their Lotto tickets in their purse or wallet, so now's a great time to clear out those old receipts and find any Lotto tickets you haven't checked yet.

"Some big winners have kept their tickets in some rather unique places, even before they knew it was a winner. So who knows? There could be $6.5 million sitting in an odds and ends draw or under a mattress somewhere in Gisborne. One past winner even kept their ticket in a Bible."

This is the fourth time Powerball First Division has been won so far this year.

"There have been some amazing stories from this year's Powerball winners about how the wins will change their lives. One winner was even expecting their first baby.

"We're sure Gisborne's newest millionaire will be just as thrilled about the big win. All they need to do is claim the prize so they can begin making their dreams a reality."

Anyone who purchased a ticket from Grant Bros in Gisborne is encouraged to write their name on the back of the ticket and check it immediately at any Lotto outlet, online at MyLotto.co.nz or through Lotto NZ's ticket-checker app.

Players can phone Lotto on 0800 695 6886 if they want to enquire about the best way to claim a prize.