A very fortunate Mega Millions winner who struck the $1.34 billion jackpot is suddenly a billionaire, and they might not even be aware of it.

According to the Illinois Lottery, the winning ticket was bought in july by an Illinois citizen at a Speedway petrol station in Des Plaines, roughly 20 miles west of Chicago.

However, an Illinois Lottery representative says as of September 4 they still haven't claimed their prize.

Officials from the lottery are currently advising everyone in the state to check their old tickets one last time to make sure they don't still have a winning ticket.

The winner gets 60 days from the date of the draw to select the cash option or annual instalments, even though they have 12 months from that date to receive their reward.

An estimated $742.2 million will be paid out under the lump-sum cash option.

In the lottery's 20-year history, this jackpot is the second-largest.

According to Mega Millions, there is a one in 302,575,350 chance of winning the jackpot

In 2016, a Powerball prize of $1.586 billion had the highest jackpot of any American lottery game.

What would happen if the Mega Millions prize went unclaimed?