A cancelled train to Reading led Bansky to paint a £15m piece of graffiti on the town’s disused prison, the artist has revealed.

Banksy pledged on Sunday to buy the prison for £10m and turn it into an arts hub, but they had “very little interest” in the area until a rail replacement bus service took them past its walls.

Now the stencil used to make the artwork, named ‘Create Escape’, could raise the money needed to buy the building and save a significant piece of Reading’s history.

Reading Chronicle: Artwork graffitied by Banksy on HMP ReadingArtwork graffitied by Banksy on HMP Reading

“I had very little interest in Reading until I was on a rail replacement bus service that went past the jail,” said Banksy.

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As soon as the artist saw it, they clambered over the passenger next to them to get a closer look.

“It’s rare to find an uninterrupted 500m-long paintable surface slap bang in the middle of a town.

“I promised myself I’d paint the wall even before I knew what it was. I’m passionate about it now, though.”

Reading Chronicle: An award-winning photograph of Reading Gaol taken by Matt EmmettAn award-winning photograph of Reading Gaol taken by Matt Emmett

Banksy’s interest in HMP Reading, popularly known as Reading Gaol, is linked to one of its former inmates, Oscar Wilde, who was incarcerated for his sexuality in the late 19th century.

Wilde’s imprisonment led him to write The Ballad of Reading Gaol.

“Oscar Wilde is the patron saint of smashing two contrasting ideas together to create magic,” Banksy said.

“Converting the place that destroyed him into a refuge for art feels so perfect we have to do it.”

Banksy’s vision depends entirely on the Ministry of Justice. The artist’s funds would prop up a £2.6m bid made by Reading Borough Council, who also want to see the jail become an arts hub.

The MoJ twice rejected their proposal because private developers could offer more, Reading East MP Matt Rodda suggested.

Banksy’s intervention means the bid would meet the Government’s asking price, but the MoJ told the Chronicle "the deadline for bids has passed." The Chronicle has asked for clarification.

Save Reading Gaol campaigner Linda Saul remains hopeful.

“The Ministry of Justice has always said that they would sell the gaol to get best value for the taxpayer,” she said.

“This offer from Banksy provides both the funds which the MoJ require, and an opportunity for a longer term economic boost that a world class arts centre with strong associations to Oscar Wilde and Banksy could bring.”

The future of the prison remains uncertain but, after Banksy’s chance encounter, Reading’s penchant for cancelling trains could just save it.