A piece of street art believed to be by a mysterious artist dubbed the “female Banksy” is about to go to public auction – leaving the graffiti star “beside herself”.

Islington Gazette: The street piece signed by Bambi in St Philip's Way, IslingtonThe street piece signed by Bambi in St Philip's Way, Islington (Image: Archant)

Bambi, who keeps her real identity a closely guarded secret – other than to admit that she is in fact also a well-known pop star – is trying to stop the piece from going under the hammer.

The piece, which appeared overnight on a garden door in St Philip’s Way, Islington, a number of years ago, depicts a crying baby sat underneath the slogan, “Top Fashion Accessory 2011”.

The property’s owners, builders Shaun Turner, 34, and Ross Field, 30, eventually took down the door after an endless stream of people photographing, enquiring about and even trying to steal the image. They have now decided to sell the piece as they have moved house.

The artwork is being sold by Rosebery’s auction house in West Norwood tomorrow where it is expected to fetch at least £1,000 to £1,500 – if not more.

But Bambi – who has had private commissions from stars such as the model Kate Moss, the actor Brad Pitt and the singers Robbie Williams, Mark Owen, Rihanna and Adele – is annoyed that the artwork will no longer be on public view.

Tweeting last week, she said: “I am very disappointed and upset that a street piece allegedly by me on a door in Islington should now come up.”

Her manager Lenny Villa, of Villa Framing in Caledonian Road, Islington, added: “She is quite upset that it’s coming up for auction. It’s a street piece and it’s meant to be left on the street for everyone to enjoy. The street is the gallery of the public. We are asking the auctioneers to withdraw it.

“Also, it hasn’t been authenticated. The auctioneers haven’t even asked for it to be authenticated and she is not saying one way or another unless she sees it.

“If someone had asked her, and the proceeds were going to Great Ormond Street Hospital or Dimbleby Cancer Care – which are her favourite charities – that would be different.

“She is beside herself.”

Last year, a framed portrait of the Queen by Bambi – entitled Diamonds are a Girl’s Best Friend – was sold in aid of Dimbleby Cancer Care, raising £11,250.

Bambi was born in Hoxton and attended Central Saint Martins College of Arts and Design – ending up a becoming a famous singer.

The keep fit fan now splits her time between her home near Liverpool Road, Islington, Los Angeles and the south of France.

“If you knew who she was, you would probably fall on the floor,” said Mr Villa.

Bambi decided to also turn her hand to art and her first piece of street art was a picture of a former soldier holding a dog, entitled Hero to Zero, in Primrose Hill. Since then, her graffiti images have included a portrait of Prince William and Kate Middleton, captioned “A Bit Like Marmite”, at the corner of Liverpool Road and Offord Road.

Michael MacDonald, co-founder of valuation and selling service Antique Vault, who was asked by Mr Turner and Mr Field to help deal with the piece, said the artwork currently for sale could fetch much more than £1,500 if Bambi confirmed it was hers.

“Her gallery work starts from £1,500 and goes up to £80,000 or £150,000,” he said. “But this one is important because it’s her first street piece to come under the hammer. None of her street pieces have ever come up before.”