His work sells for thousands of pounds and he is feted by the Hollywood elite, yet the identity of guerrilla artist Banksy remains shrouded in mystery.
Now a photograph has emerged which some people claim could show the reclusive artist at work on a London street.
The photograph, taken by a passer-by in Bethnal Green, shows a man at work with an assistant, scaffolding and a truck.
Banksy made his name with stencils and subversive art in public spaces but fiercely guards his true identity.
The photographer, who wishes to remain anonymous, is familiar with Banksy's work and took the shot as she was passing the artist at work.
The mural depicts double yellow lines veering off a road and up the side of a building, creating an outline of a flower. A stencil of a painter sits beside it.
But like some of his stencils that appear periodically around his home city, authenticating the image as "Banksy" could prove difficult.
The completed mural shows a painter and a flower
While his anonymity has captured public imagination in the artist and his work, it leaves him open to copycats.
A recent auction of 10 pieces of original Banksy art sold for more than £500,000 in Bonhams, London.
He has also become a favourite with Hollywood stars, with Brad Pitt and Angelina Jolie buying his work at a recent exhibition in Los Angeles.
A possible new piece of his work appeared in his home city of Bristol earlier in the month opposite the Children's Hospital.
It shows an armed police officer with a child about to burst a paper bag behind him. Hospital workers said they liked the piece.
But in Tower Hamlets a decision has been made to treat all of Banksy's stencilled artwork as graffiti to be painted over.
A spokesman for Tower Hamlets Council said: "In this case, Banksy has sought permission from the owners of the privately-owned building for his latest work.
"We do however need to look at the issue of the yellow lines as we have a legal obligation to reinstate the bit of the double yellow lines which has been painted out.
"As ever, priority is given to the removal of offensive graffiti."