Banksyâs parody of Demi Mooreâs Vanity Fair magazine cover could fetch £3 million at auction.
The two-metre-tall canvas was unveiled in the graffiti artistâs debut US exhibition in 2006.
It features a naked, heavily pregnant figure clutching her belly but wearing the mask associated with Banksy and smoking a cigarette.
In a poster set against the backdrop of the Hollywood sign, the image was also used to advertise the exhibition, which attracted 30,000 visitors, including Brad Pitt, Angelina Jolie  Keanu Reeves and Cameron Diaz.
Emma Baker, head of contemporary art evening sales at Sothebyâs London said the painting âembodies the tongue-in-cheek humour, the outrageousness of Banksy in that show. Heâs poking fun at celebrityâ.
And she added: âIt works on many levels, not just parody.
âYou can almost see it as like a modern day fertility goddess, especially in a fine art context.
âImages of pregnant female embodiment arenât very common across the history of artâ¦
âThis is coming at it from a very different angle and itâs very outrageous, but at the same time itâs a painting and itâs a work of fine art.â
She added: âThe monkey mask is totally synonymous with Banksy, thatâs his proxy as a disguise â¦Â Any photoshoot where Banksy has to represent himself, you see him wearing this monkey mask.â
The exhibition featured a real-life Indian elephant, with a statement: âThereâs an elephant in the room⦠Every day hundreds of people are made to feel physically sick by morons at art shows telling them how bad the world is but never actually doing something about it. Anybody want a free glass of wine?â
The canvas is being sold by a private owner and will be going to auction for the first time.
Original Concept for Barely Legal Poster (After Demi Moore) will be offered at auction in London on March 25 as part of Modern Renaissance: A Cross-Category Sale. Â