While a packed room full of art lovers watched the bidding climb for the coveted piece Girl With Balloon, it seems its famed but mysterious artist was watching, too.

Speculation is growing that Banksy, the world-famous guerrilla artist whose identity remains unknown, was sitting in the Sotheby’s auction in London on Saturday as his work went on sale.

And some are speculating that it was he who remotely triggered a shredder built into the frame of the iconic piece, just as the hammer fell on its $1.4 million sale.

For a moment, there was confusion as a loud alarm began to sound and the 2006 stenciled spray paint artwork slid halfway down through the razored jaws of the shredder.

But it was quickly evident that one of the art world’s most fascinating figures had orchestrated his most daring and brilliant stunt yet.

“It appears we just got Banksy-ed,” said Alex Branczik, Sotheby’s director of contemporary art in Europe.

Initial concern for the unlucky new owner of the piece soon evaporated, as art experts revealed that the half-destroyed work was probably now worth more.

“The successful bidder was a private collector, bidding through a Sotheby’s staff member on the phone. We are in discussions about next steps,” the auction house said in a statement.

It is widely accepted that Banksy’s street art career began in the early 1990s in Bristol in the United Kingdom, as part of the local DryBeadz graffiti crew.

Early in that decade, he is said to have met local photographer Steve Lazarides, who began selling his prints and eventually became his manager up until 2008.

By 2000, Banksy had adopted his now-signature style of stenciling, and his works became widely known in Bristol and London.

He has made his marks on cities around the world with politically themed paintings.

From traveling to Palestinian territories and creating large-scale murals on the Israeli West Bank wall to painting an elephant for a live event in Los Angeles to highlight world poverty, he has been prolific and controversial.

In 2005, he orchestrated one of his first major stunts — hanging a canvas of a 19th-century heroine wearing a gas mask on the wall of the Metropolitan Museum of Art in New York.

A year later, he released an inflatable doll dressed as a Guantánamo Bay prisoner at Disneyland in California.

He held multiple exhibitions in the UK and US throughout the 2000s, and his profile rose after celebrities began snapping up his pieces.

Suddenly, Banksy works were fetching tens of thousands of dollars at renowned auction houses, and the mysterious street artist was world famous.

Other major or notorious undertakings included Dismaland, a large-scale installation poking fun at Disneyland, and an opening sequence for “The Simpsons.”

In 2010, the documentary “Exit Through The Gift Shop” premiered and was a global sensation, earning an Oscar nomination and placing further pressure on Banksy’s anonymity.

Despite his success and growing prominence, Banksy has managed to keep his identity a closely guarded secret.

Some people are aware of who he is — associates and fellow artists — but have proven to be fiercely loyal to his wishes to stay a secret.

In 2008, the name Richard Gunningham was the first to emerge as a strong possible candidate to be the artist’s identity.

Researchers at Queen Mary University in London concluded that Gunningham was likely to be the art legend, although the man himself denied it.

“I’d be surprised if it’s not (Gunningham),” Steve Le Comber, one of the scientists, said to the BBC at the time.

In 2017, Bristol DJ Goldie seemed to slip up during an interview and name Massive Attack member Robert Del Naja as Banksy.

However, it was years before that rumors about Del Naja began to swirl when Banksy works popped up in cities where Massive Attack was touring at the same time.

He dismissed the speculation, saying that he’s friends with Banksy though.

Some in the art world have even speculated that there is no Banksy — or rather, no one artist, but a collective of like-minded thinkers who each take turns being him.

Various grainy pictures and video clips purporting to show Banksy in the act have surfaced over the years, but no clear conclusion has been reached as to his identity.

Yesterday, Banksy posted a video on his Instagram account explaining how he installed the shredder in the frame without anyone knowing.

The clip shows him placing the blade and later cuts to footage shot inside the auction room of the moment the shredder does its job.

Internet sleuths located another image of the incident, showing a man with a camera phone videoing it. His screen is visible and that angle is similar to one in footage in Banksy’s video.

Or is it a man sitting in the audience, a big grin on his face, as has been speculated in the British press? The image, taken from a screenshot of footage, bares a passing resemblance to Gunningham, but the artist’s spokesperson denied it is him.

Or perhaps Banksy sent an associate to press the button on the shredder remote when it sold?

“A man dressed in black sporting sunglasses and a hat was seen scuffling with security guards near the entrance to Sotheby’s shortly after the incident,” Art Newspaper also reported.

Whoever is behind Banksy’s artworks, they continue to garner plenty of attention and an ever-increasing amount of money when sold.

When Forbes magazine estimated Banksy’s personal wealth at around $18 million, he responded with regret, saying he wished his works were worthless.

After Saturday’s stunt, he borrowed a quote from Picasso and wrote on Instagram: “The urge to destroy is also a creative urge.”