A “stunned” homeowner unearthed a hidden Banksy mural on their wall and now plans to sell it for a staggering amount. Initially sprayed onto an office building in Holywell Row, Shoreditch in 2006, the creation was even signed by the famous Bristol graffiti artist, featuring Apache attack helicopters adorned with pink bows. Fans flocked to see Holywell Row Happy Helicopters, much to the previous owners’ annoyance.

They grew so frustrated with people showing up at their doorstep that they made the unusual decision to paint over the masterpiece. The house was then sold without the new owner knowing about the famous artwork hidden beneath.

Fortunately, the new owner was a Banksy fan and happened to be flipping through one of the artist’s books when he saw his building. He wasted no time in paying an art restorer to return the piece to its former glory.

It is now expected to fetch up to £700,000 at auction. The seller, wishing to remain anonymous, told the Sun: “We were astonished to discover that our office building was the canvas for a work of art of this significance, and moreover, it had been painted over by the previous owner.

“We wanted to ensure the integrity of the piece, so we approached restoration specialists to find the best way to preserve it for future generations.”

He added that ‘no one had previously attempted to rescue a fragile work of high-profile street art like this’. The piece was ‘painted on render’, so they decided to remove it in sections.

Chris Bull from The Fine Art Restoration Company, who worked on the project, said: “Preserving Happy Choppers took more than a year. Previous paintovers and local graffiti were also removed without disturbing Banky’s original stencil.

“Since these murals don’t use a medium traditionally found in art, our conservators studied the chemistry of the original pigments and developed new techniques suitable for the safe handling of spray paints. One of the many challenges we faced was that the work was sprayed on plaster, and structurally it couldn’t be removed in one piece due to the likely risk of it falling apart. It had to be decided to remove it in sections.”

The piece will be auctioned on March 20th.