Image copyright Tony Huggins-Haig Gallery Image caption 'I don't need it at my time of life,' wrote J of the rare fiver. 'Please use it to help young people'

An Irish woman who found a rare five-pound note engraved with a portrait of Jane Austen has donated it to charity.

The note, worth an estimated £50,000, was found in Northern Ireland by a woman known only as "J".

She sent the fiver back to the Scottish gallery it came from, and asked for it to be used to benefit a charitable cause.

"£5 note enclosed, I don't need it at my time of life. Please use it to help young people," she wrote.

The anonymous benefactor is known to be from County Donegal in the Republic of Ireland.

The Tony Huggins-Haig Gallery, in Kelso, Scotland, told BBC News NI the five-pound note would likely be auctioned off in aid of Children in Need.

Image copyright Ferguson Media Image caption The five-pound notes feature a tiny, engraved portrait of Jane Austen

The gallery created the notes in conjunction with Birmingham micro-artist Graham Short.

Just four notes were specially engraved and spent in each of the home countries.

The first was found in a café in south Wales in December, with the second discovery coming in Scotland inside a Christmas card the same month.

England is now the only area yet to discover its jackpot Austen note.

Image copyright Tony Huggins-Haig Gallery, Image caption The woman sent the gallery a picture of the note with a dated copy of her local newspaper

However, it is Ireland's anonymous donor who is causing the biggest stir after she discovered the rare fiver - and handed it back.

According to the gallery, the woman got in touch in mid-January to tell them she had found the note while visiting Enniskillen in County Fermanagh.

The artist, Graham Short, had previously told the BBC that he spent it "in a small bar called Charlie's Bar".

When the gallery asked the woman to prove her find, she sent them a picture of the note, verifiable through its serial number, along with a dated copy of her local newspaper, the Donegal Democrat.

Michael Huggins, the gallery's assistant manager, said the woman then asked for a couple of weeks to "mull over" what she might do with it.

"Then we received this note in the mail along with the fiver," he told BBC News NI. "The note just said she wanted it to be used to help young people."

Image copyright Google Image caption Charlie's Bar in Enniskillen - is this where the fiver began its Northern Ireland journey?

There are few clues as to the identity of the unidentified Donegal donor.

The woman spoke on the phone to gallery artist Tony Huggins-Haig, Michael said, who described her voice as "soft" and "older".

"With that and the note when she refers to her age, we think it's an older woman," he added. "But, all we know is that she is from County Donegal and that she wants the money to go to benefit young people."

He added that the gallery had been in touch with Children in Need, and it's likely the note will be auctioned with an added bonus.

"It seems we'll auction it off, but we've also spoken to the artist Graham Short about creating another one-off note as well. So we'll auction both off together."