The anonymous artist painted one of his signature rats on the set of the drama, filmed in his home city of Bristol, which was painted over by Walken’s character in the final episode.
A spokesperson for the show said: “We can confirm that the artwork at the end of The Outlaws was an original Banksy, and that Christopher Walken painted over that artwork during the filming of this scene, ultimately destroying it.”
Written and directed by Stephen Merchant, The Outlaws follows a group of minor criminals forced to complete a community service sentence.
In the last episode, Walken’s character uncovers a Banksy rat on the building they’re refurbishing. After asking his probation officer Diane (Jessica Gunning) whether he should paint over the rat, who is distracted and unaware that it’s painted by Banksy, he’s instructed that all graffiti should be removed.
The show also stars Rhianne Barreto, Gamba Cole, Darren Boyd, Clare Perkins, Eleanor Tomlinson, Dolly Wells and Ian McElhinney. The show was renewed for a second series in January this year.
Walken recently discussed how he missed out on playing Han Solo in the original Star Wars, stating that he’s “very glad Harrison Ford got it”.
He added: “I did audition [for Star Wars], but I don’t think I came remotely close to getting the job. About 500 other actors auditioned, so it wasn’t as if it was down to me and somebody else.”
Last month, a shredded Banksy artwork titled ‘Love Is In The Bin’ sold for £16million at auction, which was what remained from the artist’s live destruction of his previous piece, ‘Girl With Balloon’.
The Outlaws is available to stream on BBC iPlayer.