BANKSY'S graffiti of sneezing rats on the London Underground worth an estimated £7.5million was scrubbed off by mistake.
The spray painted series of rodents in carriages were part of a message urging Londoners to wear masks.
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A TfL spokesperson confirmed no one knew Banksy had left work on the Tube until a video emerged yesterday, and so it was dealt with as regular graffiti would be - with cleaners having no clue what they were removing.
Banksy, himself masked up, took to the network days ago to daub a carriage with Covid-infected vermin.
Joey Syer, Co-founder of - which has more than 25 years of experience of art dealing and specialises in Banksy's work - believes it could have been worth millions.
He told the Sun Online: "Its a huge shame and opportunity lost for Londoners that the latest Banksy work has already been removed by the anti-graffiti teams at TFL.
"Of course, we understand why, and we understand it's highly likely whoever removed it was following procedure and had no idea they were destroying a Banksy.
"Had TFL management known, and had the opportunity to remove and protect the installation we estimate it's value as a complete package to be in the region of £7.5million.
"Sadiq Khan must be kicking himself, but Banksy has yet again proved his ability to entertain and make a statement with such daring and style."
A Transport for London source the cleaners had no idea of the significance of the work, saying: “When we saw the video, we started to look into it and spoke to the cleaners.
Had TFL management known, and had the opportunity to remove and protect the installation we estimate it's value as a complete package to be in the region of £7.5million.
Joey Syer
"It started to emerge that they had noticed some sort of ‘rat thing’ a few days ago and cleaned it off, as they should."
It comes after Mayor of London Sadiq Khan handed over control of the capital's transport system in a row over cash.
The Government gave him a £1.6bn bailout last month to keep the network afloat after the mayor insisted it was cash-strapped.
A TfL spokesperson said: “We appreciate the sentiment of encouraging people to wear face coverings, which the vast majority of customers on our transport network are doing.
'In this particular case, the work was removed some days ago due to our strict anti-graffiti policy.
"We’d like to offer Banksy the chance to do a new version of his message for our customers in a suitable location.”
They added when graffiti is spotted, the train is pulled out of service and into a depot where cleaners will go on and wipe it off before the train goes back into use, usually on the same day.
BANKSY ON BOARD
In a video shared to the artist's Instagram, the anonymous graffiti genius is seen entering a carriage in a hazmat suit, face mask and goggles.
It's suggested Banksy had disguised himself as one of TFL's deep-cleaners.
As commuters look on he paints stencils on train walls and windows and is also filmed getting on and off at various stops.
The message of the masterpieces - a rat spraying gunk and snot across a carriage, another rat frolicking inside a discarded surgical mask and another using PPE as a parachute - is to wear a mask.
The artist captioned the post: "If you don't mask you don't get."
Brits were told by the Government they would need to wear face coverings on public transport back in June, and new measures have since been introduced to enforce the wearing of face coverings in shops in a few weeks time.
In the footage, commuters try not to stare as he sprays a tag on the back wall of a Tube carriage, dripping in what looks like infectious-looking slime.
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Other commuters rush past the street art legend as he heads up the stairs to the next platform - his paints cleverly disguised as disinfectant spray gear at his side.
The video ends with a shot of the slogan "I get lockdown" sprayed on a wall at - from the sound of the announcements - Euston Square Station.
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