Your new £5 note could be worth up to £50,000 if it has this marking

First came the £5 serial number game.

This had us scrambling to see if any of our crisp new notes had the coveted 'AA01' serial number so we could flog them to ‘collectors’ apparently prepared to pay hundreds for them.

Now there’s a new ‘is my £5 worth a lot more than £5’ game. And this one could be a lot more lucrative.

Micro-engraver Graham Short has put into circulation four notes with miniature engravings of Jane Austen.

The painstaking designs have been etched next to the picture of Big Ben and Winston Churchill. They are barely visible to the naked eye but can be seen in bright light.

The 70-year-old has also engraved quotes from Austen's novels into the notes, which are estimated to be worth up to £50,000.

The master engraver is famous for works such as etching the Lord's Prayer onto the head of a pin and some of his previous works have fetched as much as £100,000.

Explaining to The Telegraph why he chose the new £5 notes for his latest work, Short said:

"I'm always looking to do something different.

"When I saw the new £5 note, I thought, 'Wouldn't it be good if I could engrave something on it.'

"I didn't know what at first, but then I found out that next year is going to be the 200th anniversary of Jane Austen's death and her image is also going to be on the new £10 note, which is coming out next year, so it ties in quite nicely with that."

Short goes to extreme lengths to create his microscopic works including having Botox injections between his eyes to stop them twitching and wearing a stethoscope so he can work in between his heart beats.

So you can see why these notes could be worth a fair whack.

Don't all rush for your wallets and pockets at once.