A group of joggers powering through inner Sydney today are on the hunt for a mystery millionaire who has $100 million waiting for them.

A person who bought a winning Powerball ticket at a Bondi Junction newsletter on June 12 remains unknown two months later, and lotto authorities are stepping up their efforts to find them.

Today, that will take the form of a group of people in running gear taking a brisk path through the city streets, hoping to “jog” the memory of the anonymous ticket-buyer.

A $100 million Powerball winner is sought in Sydney. (The Lott)

“It has now been 63 days since the elusive ticket holder won this massive $100 million prize and throughout that time, we have been eagerly waiting to unite the winner with their Powerball windfall,” The Lott spokesperson Matt Hart said.

“Each day during the past nine weeks, we’ve been asking ourselves – is today the day the winning ticket is presented?”

The person who bought the ticket from Bondi Junction Newsagency on Oxford Street now shares the title of Australia’s third-biggest lottery winner.

How Australia’s lotto winners spent their cash

They have six years to pick up their new fortune.

“Today, we’re hosting a Memory Jog around the streets where the winning entry was sold in the hope that seeing our team running around Bondi Junction sparks a memory and spurs players to hunt for unchecked lottery tickets,” Hart said

“In previous cases where people have come forward weeks, months and even years after the draw to finally claim their prize, they’ve told us the winning ticket was hiding in plain sight the whole time – in their wallet or purse, on the fridge, or just lying around in a drawer.”

The winning numbers in the draw on Thursday, June 12, were 28, 10, 3, 16, 31, 14 and 21. The Powerball number was 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.