A fake banknote produced by Banksy – a tenner featuring Diana, Princess of Wales – has been acquired by the British Museum and now resides in its permanent collection of coins and other currency.

The £10 note was first produced by Banksy (and duplicated, to about £1 million worth) to be thrown off a building, but when some of the notes were handed out at Reading Festival and people began using them to buy drinks, the artist realised he could be jailed for forgery and promptly took them out of circulation, so to speak.

That didn’t stop Tom Hockenhull, the curator of modern money at the British Museum, from wanting to get his hands on one though, to add to the museum’s collection of “skit notes” (that’s banknote parodies, to those not down with the currency lingo). The problem was, for Hockenhull, making sure he got a genuine “Di-faced Tenner”.

“Because (Banksy) was effectively producing them as photocopies,” he tells the Guardian, “anyone else could do that as well, so there was no way to really verify whether they were from Banksy or not.”

Now, finally, the British Museum seems to have received one from a source close to Banksy. It’s not the first time they’ve had dealings with the artist, though. In May 2005, one of Banksy’s infamous pranks saw him add “Peckham Rock” – an artwork depicting a figure with a shopping trolley on a lump of concrete – to the museum’s collection of cave paintings. It managed to go unnoticed for three days before staff removed it, and revisited the museum as part of Private Eye editor Ian Hislop’s exhibition about dissent.

At least – from the museum’s standpoint – this new Banksy acquisition is on their own terms.