Rare errors on limited edition $2 Olympic coins released through Woolworths supermarkets could make them worth thousands of dollars

The coins were handed out at random to shoppers who paid with cash in July and August.

Shoppers who paid with cash at Woolworths supermarkets during the Tokyo Olympics could be sitting on a valuable coin error that might fetch them thousands of dollars at auction.

The supermarket handed out limited edition $2 Olympic and Paralympic coins to customers who paid with cash at the register during July and August.

Yahoo Finance has obtained several images of the error coins, with collectors noting they are seeing more and more pop up.

Some appeared to have a bullseye error, where the coloured motif was printed on the wrong side - in this case on King Charles' face, which could be an Australian first.

Mark Nemtsas from The Purple Penny told Yahoo Finance the bullseye could fetch between $1,000 to $3,000 at auction if it's legitimate.

Other bullseyes have sold for nearly $6,000.

Have you uncovered a valuable item unexpectedly? Email stew.perrie@yahooinc.com

"Fantastic find," one collector said.

"Keep hold of that one," said another.

"This coin is terrific to have in one's possession, very envious," noted one man, claiming he's seen "quite a few bullseyes" in this release.

This means there could be more out there.

Some other errors are not as noticeable. Another coin distributed in the major supermarket had the C missing from Charles and only the RS in dollars printed on the face side.

Nemtsas said this was the result of a die-fill error and had an estimated value of $30 to $50.

"Grease or oil fills in the letters or other features on the dies and when the coins are struck those features are not formed on the coin because the grease or oil is incompressible," he explained.

The Royal Australian Mint told Yahoo Finance it was looking into the errors when asked how widespread they may be.

Why are bullseye errors so valuable?

Coin expert Matthew Thompson of Thompsons Coins and Collectables told Yahoo Finance it was “very uncommon” for the Royal Australian Mint to make mistakes like this one, which was why the coins were so popular and could be sold for thousands of dollars.

“The Royal Australian Mint has some of the highest quality coins in the world and stringent procedures to stop these from happening,” the Melbourne collector said.

“So on the odd occasion it does, there’s a lot of excitement in the industry. But it can be difficult to research as the mint don't really promote their mistakes.”

He said there's no way to know how many there are out there.

“No one knows for sure which is sort of why they’re so popular and collectable because the amount out there that’s available would be really small. But no one knows a definitive production run on them,”

Downies Collectables recently sold an uncirculated version of the bushfire tribute $2 coin for a staggering $5,950.

Major warning about bullseye error coins

While the attractive price tag might make every Aussie search through their coin collection immediately, it's worth being aware of a scam that has been circulating regarding bullseye errors.

Fake versions of the firefighter coin were being sold to unsuspecting Aussies where sellers manually transferred the fireball paint onto the other side of the coin.

Nemtsas told Yahoo Finance this proliferation of fake bullseyes caused the market to "collapse", but real ones can still fetch a high price if they're authenticated.

Thompson encouraged collectors to go to an expert for a professional opinion.

“It’s important to be super wary with errors like that. People get caught out from time to time and end up losing thousands so it can get pretty risky,” he said.

How can I get the Olympic Woolworths coins?

The coins were released through Woolworths supermarkets, with some limited edition albums also available from the Mint and Australia Post.

Each fortnight there was a new coin added into circulation. That time is over now though.

There were three Olympic designs and one for the Paralympics.

The ‘Allezaus’ coin referred to the popular European sports chant ‘Allez’ meaning ‘Let's Go’. It featured the team mascot, BK the Kangaroo, break dancing, which was a new sport at the Paris Olympics.

The ‘Olympism’ coin featured a Parisian Boxing Kangaroo, while the final ‘Paralympics’ coin had the team mascot, Lizzie the frill-necked lizard, playing the sport of Goalball.

Some customers expressed frustration over Woolworths policy around how they could be distributed by cashiers.

The supermarket said “all coins are distributed by chance and are only available while stocks last”.

“My local stores have bags in the till but won’t open them. It’s ridiculous. They aren't ‘allowed’ to choose which coins I get, nor can they open a bag of them if they already have other coins in the till,” she said.