Bristolian street artist unveiled New York mural in March in protest against her arrest

Prices for larger works by the Bristolian street artist could fetch more than £5m

Highest price to date is $1.9m, but Steve Lazarides says some paintings have a £2m-plus price tag

The UK graffiti artist has put up a string of murals and stencils in the city

Street artist and film director staged performance that was filmed for BBC Two documentary which will air this weekend

The Art Newspaper team assesses the art world's fortunes in a turbulent year

Work was revealed by actor dressed as Queen Elizabeth II, marking 100th anniversary of contentious declaration

British street artist’s latest works poke fun at the zero-tolerance approach to graffiti around the London gallery

Meanwhile, a new show organised by the mysterious artist proves to be a blockbuster

Unauthorised works by the anonymous graffiti artist have been sold on the internet; prices for these have been illegally inflated with fake bids