Valuable art works by graffiti artist Banksy will be preserved on the walls of a city centre exhibition centre.

The internationally-celebrated artist whose work fetches six-figure sums at auction paid a clandestine visit to the Square Mile just before the opening of the Barbican’s blockbuster Basquiat: Boom for Real exhibition opened last year.

He created two works overnight in homage to the pioneering New York artist Jean-Michel Basquiat and took the Barbican management team by surprise.

The exhibition proved to be the most successful in 35 years of art shows at the Barbican and 216,389 visited it. Many of them also looked at the Banksy works, and it also got extra publicity because of the Banksy work.

The first used a character from Basquiat’s own work but showed him being searched by police.

Banksy attributed the work via his own Instagram account and captioned it 'Portrait of Basquiat being welcomed by the Metropolitan police'.

The Banksy artwork has drawn the crowds

The second artwork shows five people waiting for a ferris wheel and uses the symbol of the three-pointed crown which Basquiat often used in his own work.

The US artist Danny Minnick subsequently added his own work.

The Barbican Centre Board agreed to a long-term strategy to protect the street level paintings on the side of the Barbican Exhibition Centre.

During the exhibition, it swiftly arranged security.

There were also concerns that the City of London’s cleaning team might remove it, but the work was protected.

Other artists have tagged it, but these were removed by the Barbican.

The art has attracted 296,000 likes and 2,000 comments on Banksy’s official Instagram account.

Last month, Banksy’s Canvas of Girl With a Balloon self- destructed to the consternation of the art world after it fetched £1m at auction.

Jonathon Poyner, the Barbican’s director of operations and buildings, told the board meeting on Wednesday, November 21, the cost of a protective Perspex covering was in the “minor hundreds”.

Board chairman Deputy Dr Giles Shilson said: "The art works have proved very popular with the public. There was a scramble when it was thought the cleaning team would scrub off half a million pounds of art work by breakfast time."

Councillor Vivienne Littlechild (Cripplegate) saids she was aware of a round robin letter complaining about people collecting on the pavement and making noise as they looked at the art.

Dr Shilson said he received one complaint "from somebody who said it was grotesque".

He added that, like the attention when Benedict Cumberbatch appeared in Hamlet at the Barbican, the "initial flurry of interest" calmed down.

"People do stop and take photographs but I think they are not stopping there screaming," he said.

The board approved the Barbican Centre’s work to preserve the paintings and meet any costs from their budget.