Banksy reveals how he built his 'self-destructing' painting that shredded after auction.

Image via Peter Macdiarmid / Getty Images

Banksy, the elusive British street artist, stunned the art world on Friday, October 5, with one of his most elaborate and shocking pranks.

After the gavel fell on his “Girl with a Balloon” painting at Sotheby’s London for $1.4 million, the artwork dropped through a shredder in the frame, reducing half of it to ribbons.

The “Girl with a Balloon” image, which first debuted in 2004, has become one of the artist’s most iconic creations. Its stencil has been repeated in an edition of 150 prints and 25 numbered paintings by Banksy.

While most would assume the anonymous buyer would be furious at the destruction of his or her recent purchase, some believe the shredded artwork immediately increased in value due to its historical significance.

“It was a brilliant PR stunt,” Offer Waterman, a dealer in 20th-century British art, who attended the art auction, told The New York Times. “It’s going to elevate his prices. It’s become worth more as a conceptual moment than as a work of art itself.”

While Banksy’s stunt has been called a conceptual master stroke, pulling it off was no easy task. After the gavel fell on the painting, an anonymous attendee hit a radio-controlled device that dropped the piece through a shredder at the bottom of the frame.

The day after the event, Banksy released a quick video revealing how he did it.