Two of the special notes remain in general circulation
One British student received a very special Christmas present this year - a £5 note actually worth an estimated £50,000.
The note, which was found in Scotland inside a Christmas card sent by a relative, is one of only four of the new plastic banknotes which feature a minute depiction of Jane Austen by specialist engraver Graham Short.
It is the second of the notes to be discovered - another was found in Wales this month.
Austen's 5mm portrait appears on the transparent section of the note, surrounded by a unique quotation from her works.
Tony Huggins-Haig, whose Gallery launched the project, told the BBC he had been in contact with the recipient, who wishes to remain anonymous.
"When somebody opened their Christmas card from a loved one, it was contained in that Christmas card," he said.
"The person who put it in didn't necessarily know what they were doing. That's two down and there's still two out there. Keep checking your change."