When he first began redecorating walls and buildings in his native city of Bristol in the early 1990s, the graffiti artist known as Banksy was frequently accused of vandalising private property.

A decade and a half later, having won fame and a considerable fortune, he faces a different charge.

The graffiti artist - who fiercely defends his anonymity - now stands accused of causing gentrification. His street art is being held responsible for proposed regeneration projects; his aerosol paintings are blamed for raising house prices in formerly deprived neighbourhoods.

These charges were laid against Banksy this week by a shadowy group calling themselves Appropriate Media.

“Banksy... sells his lazy polemics to Hollywood movie stars for big bucks,” the group said, in a statement posted on their website.

“Graffiti artists are the performing spray-can monkeys for gentrification. In collusion with property developers, they paint deprived areas bright colours to indicate the latest funky inner city area ripe for regeneration. Pushing out low income families in their wake, to be replaced by middle class metrosexuals with their urban art collections.”

As proof of their resolve, early on Monday morning a member of the group attacked a celebrated piece of graffiti by Banksy in the Stokes Croft district of Bristol, partially spraying it with red paint.

This act of rebellion against the most famous painter in the graffiti establishment provoked anger in some quarters, though for some it was the first sign of a broader backlash against Banksy.

On a graffiti internet forum, aficionados and graffiti critics discussed the meaning of the “tagging” of the work, that dates to 1994 and is known as “Mild Mild West”.

One discerned a “backlash against Banksy that I’ve been aware of building in certain quarters for the last three years and we seem now to be seeing it coming to fruition”.

Another thought it a very British protest against the artist’s enormous success and “the amount of money in the game... that some graffers feel the art is being washed out with everyone cashing in”.

Mild Mild West depicts a teddy bear preparing to throw a Molotov cocktail at advancing riot police. Chris Chalkley, managing director of the People’s Republic of Stokes Croft, an organisation seeking to turn the district into “an outdoor Guggenheim of street art” told The Times: “This so-called political act is defacing one of the most political pieces of street art in the south west. That piece is about the rave scene... that was a very gentle fluffy culture, but the police were cracking down on it. It was a protest against that.”

Discovering the damage, Mr Chalkley and other members of his organisation held an impromptu meeting on the pavement in front of Mild Mild West. “We had to make a quick decision as the paint was drying fast,” he said. Having consulted various passers by, “the decision was that we should remove the red paint,” he said. Like curators addressing an act of vandalism in an art gallery, they set about restoring the piece of graffiti to its original condition.

The site of the painting has attracted development proposals for a cafe with an adjoining public “viewing gallery”, which would enclose the wall in glass. Matt Harrison, project architect for White Design, an agency involved in the proposals, admitted that graffiti could sometimes make an area more attractive to developers. “It can demonstrate the bohemian nature of an area,” he said.

However, Kevin Cox, a local estate agent, said he did not believe a Banksy could raise a neighbourhood’s property prices. “All it does is legitimise more graffiti that isn’t so good,” he said. “I wouldn’t suggest it increases the value.”

Some residents seem to disagree. In another district of Bristol, locals have framed an old piece of Banksy graffiti with a glass cover, to protect it from defacement.

Meanwhile in Liverpool late last year, estate agents said a disused pub had doubled in value to £1 million after it formed the canvas for an enormous painting of a giant rat, thought to be by Banksy.

The Times contacted Banksy through his agent today, but he declined to comment.

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