$7.2 million Lotto win remains unclaimed a week on

A winning Lotto ticket bought at Pak'nSAVE in the north Auckland suburb of Silverdale still hasn't been claimed, a week on from the result.

Lotto NZ urges anyone who bought a Powerball ticket from Pak'nSAVE Silverdale for the Lotto draw on September 12 to write their name on the back of the ticket and check it immediately.

The winner has 12 months from the date of the draw in which to claim their prize.

Big winners can also call the Lotto New Zealand helpdesk on 0800 695 6886 for information on how to claim their prize.

Kirsten Robinson, head of corporate communications at Lotto NZ, explained sometimes people didn't check their tickets very quickly.

"Powerball winners are all different - while most are quick to claim, we've had players in the past that haven't bothered checking their ticket as they mistakenly thought the prize had already been claimed."

One such unsuspecting winner was a Northland woman who took a week to claim her $8.3m Powerball prize earlier this year.

"I was talking to my daughter on the phone when she mentioned that the prize was still unclaimed," she said. "My ears perked up straight away, and I thought 'I better check mine, there's still hope'."

She offers some simple advice.

"If you find any ticket, get it checked - even if you don't think you'd ever be so lucky."

As for her words of wisdom to other winners: "Only tell your nearest and dearest. We've kept the win pretty quiet and it's been wonderful - we've ticked things off our bucket list without too much fuss."