By Fiona Pryor
Entertainment reporter, BBC News
Known for spray-painting live animals and sneaking his work into prestigious galleries, Banksy is going from strength to strength.
But very little is known about the secretive "guerrilla artist".
The subversive political messages Banksy conveys through his stencils and sculptures can be found on streets, walls and buildings across the world, from London to New York.
The live elephant was intended to represent world poverty
Last year, he left a life-size replica of a Guantanamo Bay detainee at the California theme park Disneyland.
And in 2005, he decorated Israel's controversial West Bank barrier with satirical images of life on the other side.
He has suddenly become one of art's hottest properties, with Angelina Jolie and Christina Aguilera among those who are reported to have splashed out on his work.
On Wednesday, a picture depicting pensioners bowling with bombs broke the £100,000 barrier - setting a new auction record for his works and placing him firmly in the artistic elite.
But he still tries his best to eschew the establishment he savagely lampoons.
The bomb picture sold for £102,000
After the auction, his website featured a sketch of an auction room with a message on a canvas saying: "I can't believe you morons actually buy this shit."
But while the public may have grown to love - or loathe - Banksy's public stunts, he has managed to carve a career out of remaining anonymous.
His age, real name and current location are a mystery.
But with all the publicity, there must be someone out there who knows him.
Last year, the controversial artist returned to his home town, Bristol, and left his mark on a council-owned building.
The public voted to keep the painting, which depicts a naked lover caught with his pants down, hanging from a window ledge.
Local press covered the story in great detail - but did they manage to speak to the man himself?
"No, never met him, we don't have any contact with him," says journalist Liz Beacon from local BBC news programme Points West.
"He's a real enigma and that's part of the fascination with him."
Bristol councillor Gary Hopkins - who supported the campaign to keep the naked mural - says: "I never met the chap, and never likely to meet him."
It is not just the fans who are in the dark about Banksy's background - art experts also appear clueless.
Banksy painted on Israel's controversial West Bank barrier
Mark Clark is the curator of the Arnolfini contemporary art gallery in Bristol.
"I don't know who he is - and I've never met him - although I once met his manager," he says.
"Afterwards I did wonder if it was actually him, but I am not sure."
Mr Clark believes the mysterious persona Banksy has created has helped his career.
"It was probably better for people not to know who he was as when he started, what he was doing was essentially illegal.
"But now I think it serves its purpose very well as it only increases interest around him."
Indeed, the people who work for Banksy and help promote his work are almost as hard to get hold of as the artist himself.
Agent Steve Lazarides, who runs his own gallery in London, is out of the country and unavailable for comment.
After several phone calls to Banksy's PR company JBPR, owner Jo Brooks eventually made contact - but refused to be drawn into any discussion regarding Banksy's identity.
The Banksy trail is hard to follow, and just when it seems no-one has encountered the man himself, a freelance journalist based in Bristol admits he has met the elusive artist.
Fergus Colville interviewed Banksy in 2002 for an exhibition at a restaurant in Bristol.
"I just phoned up people I knew that knew him and set up the interview, but that was before he was famous," Mr Colville says.
Bristol locals voted to keep this Banksy art on the wall
The artist is actually from Yate, just north of Bristol, Mr Colville says.
"He was very ordinary, about 5"9' and quite skinny," he says. "I've seen a photo of him since and he's filled out."
And what about his real name? "I'm not sure, but it could be Rob Banks," Mr Colville says.
He also believes Banksy's popularity is a product of hitting a nerve with the public.
"He's stumbled across a fantastic PR stunt. It's pseudo anonymity. It feeds the media's appetite, and until they find out who he is, they're not going to give up."