A stencil by the famed, secretive graffiti artist of a young boy sewing Union Jack bunting on an antique sewing machine appeared on the side of a north London bargain store last May. Soon the gritty Turnpike Lane area was drawing art lovers keen to see Banksy's typically cheeky take on the Diamond Jubilee celebrations of Queen Elizabeth II's 60 years on the British throne.
Last week it vanished, leaving nothing but a rectangle of exposed brick - only to reappear on the website of a Miami auction house. Listed as "Slave Labor (Bunting Boy)," it is due to be sold on Saturday with an estimated price of between $US500,000 ($A484,000) and $US700,000.
On Wednesday the local government authority said it planned to appeal to the auction house for the return of the mural to its rightful home.
Alan Strickland, a councillor with local Haringey Council, said the work had become "a real symbol of local pride" in an area badly hit in England's August 2011 riots.
"The Banksy created a huge amount of excitement when it first appeared, and residents are understandably shocked and angry that it has been removed for private sale," Cr Strickland said.
"The community feels that this artwork was given to it for free, and that it should be kept in Haringey where it belongs, not sold for a fast buck."
Cr Strickland said he had asked England's Arts Council for help.
The government-funded council called the loss of the Banksy "a shame" but said there was little it could do. The council has the power to stop the export of culturally significant artworks, but only if they are more than 50 years old.
The lawmaker for the area, Lynne Featherstone, says she has asked the building's owner for an explanation but has yet to receive a reply. Poundland, the store that occupies the building, said it had nothing to do with the removal.
"(It's) totally unethical that something so valued should be torn without warning from its community context," Ms Featherstone said.
Fine Art Auctions Miami said it had acquired the work legally, but gave few other details.It said in a statement that it had "done all the necessary due diligence about the ownership of the work."
"Unfortunately we are not able to provide you with any information by law and contract about any details of this consignment," it said. "We are more than happy to do so if you can prove that the works were acquired and removed illegally."
Banksy's publicist did not immediately reply to a request for comment.
The anonymous street artist, who refuses to reveal his real name, began his career spray-painting buildings and bridges in his home city of Bristol in southwest England. His 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."
Original Banksy works now sell for up to hundreds of thousands of dollars and the artist has become an international celebrity. He has created sequences for The Simpsons and directed an Academy Award-nominated documentary, Exit Through the Gift Shop.
His works are still sometimes obliterated by zealous local officials, street cleaners or - as in this case - taken off buildings along with a chunk of wall for private sale.