Banksy agreed to make art for a BBC series. Then, Christopher Walken painted over it.

One of Banksy's art pieces can sell for millions of dollars and yet one BBC TV drama painted over his signature rats for the plot. 

Actor Christopher Walken, who plays Frank on "The Outlaws," painted over the Banksy artwork during the shows final episode, BBC reported.

The comedy-drama centers around a group of unlikely misfits completing community service and is set in Banksy's hometown of Bristol. Before filming the last episode, Banksy agreed to leave his signature on the set, according to BBC.

While performing community service, Walken’s character Frank discovers a rat sitting on two spray cans signed by Banksy and asks his probation officer  if he should paint over it. She wasn't paying much attention and quickly told him to paint over it, destroying Banksy's work.

How much does Banksy's work sell for?:Banksy's shredded artwork 'Love is in the Bin' sells for a record $25.4 million at auction

Millions for Banksy's work:Banksy artwork auctions for almost $10 million, second-highest price paid for his work

The scene left viewers wondering whether the Banksy art was original, which BBC later confirmed.

“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,” a BBC statement read.

Banksy, who has never confirmed his full identity, began his career spray-painting buildings in Bristol, England, and has become one of the world's best-known artists. His shredded artwork 'Love is in the Bin' sold for a record $25.4 million while his “Show Me the Monet” sold for $9.8 million. 

Follow Gabriela Miranda on Twitter: @itsgabbymiranda