The stencil was a version of the painting The Raft of the Medusa by Théodore Géricault showing a group of desperate survivors on a raft after a wreck.
It was given a modern, refugee-themed twist - a nod to the notorious "Jungle" refugee camp in Calais that housed thousands of refugees hoping to get to Britain - with the survivors trying to get the attention of a ferry on the horizon.
It was one of three that the elusive British artist had produced in the port town in 2015 on the theme of migrants.
But the owner of the building on which The Raft of the Medusa was stencilled decided that it was more important to have his property upgraded than to preserve the work of art.
"The wall was in a very bad state, and there was graffiti and part of the Banksy work had already been sprayed over," Georges Lagouge told The Local. “You couldn’t see the ship on the horizon any more.”
"I would have been happy to have it (the mural) preserved but I contacted the town hall to ask them if they wanted to look after it and nobody got back to me," he said.
"To sell it I would have either have had to sell the whole building (made up of apartments and a pharmacy) or somehow cut out that section of the wall. It would have been too complicated," said Lagouge, who lives elsewhere and rents out the building.
So the painters were called in last week and, after removing the plexiglass that local authorities had put in place in a vain attempt to keep the mural in good shape, they painted over the work and restored the wall to its original white finish.
Pictures on Twitter showed a blank, white wall where Banksy's update on the 1819 masterpiece had previously stood (see below).
Officials at Calais town hall did not immediately respond when asked by The Local if or why the town had failed to preserve an important art work.
Its removal now leaves just two of the three murals that Banksy produced in Calais.
The best known one is of the late Steve Jobs (see below), the founder of Apple, carrying a black bag on his shoulder and with an Apple computer in his hand.
Steve Jobs by Banksy in Calais. AFP.
The work - painted on a wall under a bridge leading into the now closed "Jungle" - was a reference to that fact that Jobs was the son of a Syrian migrant to the United States.
But that work has also been disfigured, with someone spraying "London Calling" in huge letters around it and other smaller graffiti placed around it.
The most intact Banksy work remaining in Calais is an image on a building on the town’s beach of a young child gazing out to sea through a telescope. On top of the child's telescope is a vulture staring down (see below).
A Banksy artwork of a child looking out to see through a telescope. AFP.
Having a Banksy on the wall of your house can add enormous value to your property. In London, luxury developers are doing up properties where street artists such as Banksy have left their mark and using it as a key selling point that lets them hike prices.
Georges Lagouge, who had his own personal Banksy removed, says he has no regrets about the sinking of the Raft of the Medusa.
"If they (local authorities) had wanted to look after it I would have been delighted. But they didn’t. I have no regrets, but if Banksy wants to come back and do another one on my wall, he’s more than welcome," he told The Local.
by Rory Mulholland