An Australian King George V Penny Red that was printed with a sideways watermark has been valued at $100,000, after a collector failed to sell it for 99c on eBay.
The anonymous collector identified the stamp's flaw soon after purchase and immediately made it available on the internet auction site with a reserve of just 99c.
However, he was scoffed at by stringent philatelists, who dismissed his claims that it was a hitherto unknown variety.
Undeterred, the enthusiast took it to a Scottish dealer, who then brought it to the 2013 World Stamp Expo in Melbourne, where it was given its astonishing valuation.
With over a billion King George V Penny Reds issued, ordinary examples can be bought for as little as just a few cents.
It is one of the most collected of all Australian issues and therefore a rush to find similar flawed stamps will undoubtedly ensue.
The current world record for a King George V Penny Red stands at $41,041, after a mint block of four sold at a 2001 auction. Should the anonymous collector decide to part with his extraordinary rarity, it will surely break all records.
In March, part of the collection of notorious millionaire John du Pont crossed the block in the UK, with a unique 1909-1910 Australia 2d postage due selling as top lot.
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