The three works by the renowned graffiti artist and activist have been languishing in the Arches nightclub since its doors closed earlier this summer.
The building’s owners have said there are no plans to restore or remove the works for safekeeping, raising fears that they could be lost for good.
Banksy, whose works now command six-figure sale prices at auction, was a little-known street artist when he created the collection for an exhibition at the well-known Glasgow venue 13 years ago.
Two of the drawings adorn an arch-shaped dividing wall leading into the club’s toilet block, while the third is on an exterior wall in the city’s Midland Street
The two works inside depict a Mona Lisa with her head surrounded by a picture frame and, by her side, a gun-toting monkey sporting a ballet tutu. In between the Mona Lisa and the monkey, Banksy daubed in red paint: “Every time I hear the word culture I release the safety in my 9mm.” The outside wall also features the image of the monkey.
However, all three works are in poor condition, having been partially daubed over with grey emulsion paint after the end of the exhibition.
With the future of the building unclear, it looks unlikely they will be restored. The Arches complex went into administration in June after being left £500,000 in debt following Glasgow City Council’s decision to impose a midnight curfew on the nightclub.
Last month the contents of the venue were sold off at auction and now the space is empty, apart from the Banksy drawings.
Nick King, a spokesman for the building’s owners, Network Rail, said there were no plans to remove the artworks or restore them to their original condition.
He said: “The quote which The Arches management got last year to repair the Banksy work was £20,000. They really are not in the best condition.
“Network Rail is not looking at doing anything with them. Our main focus is that we now have a building to occupy.”
A youth club in Bristol was last year offered £1m for a Banksy mural on its wall. It eventually sold for £400,000, safeguarding the club’s future.
Actor Tam Dean Burn, who campaigned to save the Arches, said: “This is yet another example of the tragedy that is the Arches closure. So many great artists from so many spheres brought their creativity to the legendary venue.”