By JILL LAWLESS
Associated Press

LONDON (AP) - Art prankster Banksy has struck again.

A work by the elusive street artist apparently self-destructed in front of startled auction-goers on Friday, moments after being sold for 1.04 million pounds ($1.4 million).

The spray-painted canvas "Girl With Balloon" went under the hammer at Sotheby's in London, fetching more than three times its pre-sale estimate and equaling a record price for the artist.

Then, as an alarm sounded, it ran through a shredder embedded in the frame, leaving half the canvas hanging from the bottom in strips.

A post on Banksy's official Instagram account showed the moment - and the shocked reaction of those in the room - with the words "Going, going, gone..."

Sotheby's - which had noted before the sale that the work's ornate gilded frame was "an integral element of the artwork chosen by Banksy himself" - expressed surprise at the incident.

"It appears we just got Banksy-ed," said Alex Branczik, head of contemporary European art at the auction house.

The auction house said it was "in discussion about next steps" with the buyer. Some art-market watchers say the work could be worth even more in its shredded state.

"We have not experienced this situation in the past . where a painting spontaneously shredded, upon achieving a record for the artist," Branczik said. "We are busily figuring out what this means in an auction context."

Geneva-based artist Pierre Koukjian, who was at the auction, said the buyer was "very lucky" to own a now-historic piece. He called Banksy's prank "a turning point in the history of contemporary and conceptual art."

Koukjian, who has met Banksy, said he is sure he caught a glimpse of the artist in the saleroom amid the confusion of the moment.

"What he did is really shocking, in a good way," Koukjian said. "I think it will be historic and people will talk for a long time about it."

Banksy is not the first artist to deconstruct his own work. In the years after World War II, German-born artist Gustav Metzger pioneered "auto-destructive art," creating paintings using acid that ate away the fabric beneath.

Banksy, who has never disclosed his full identity, began his career spray-painting buildings in Bristol, England, and has become one of the world's best-known artists. His mischievous and often satirical images include two policemen kissing, armed riot police with yellow smiley faces and a chimpanzee with a sign bearing the words "Laugh now, but one day I'll be in charge."

He also has a penchant for elaborate pranks.

In 2005, he hung an image of a spear-toting ancient human pushing a shopping cart in the British Museum, where it remained for several days before being discovered. The next year he smuggled a life-sized figure of a Guantanamo Bay detainee into Disneyland, and in 2015 he erected a full-scale dystopian theme park - "Dismaland" - by the British seaside.

"Girl With Balloon," which depicts a small child reaching up toward a heart-shaped red balloon, was originally stenciled on a wall in east London and has been endlessly reproduced, becoming one of Banksy's best-known images.