The long-lost work, known as Snorting Copper, shows a policeman snorting a line of cocaine on his hands and knees. It appeared on a toilet building a decade ago, but disappeared after it was vandalised and then covered up by the local council.
The now infamous illustration was rediscovered thanks to property developers Jonathan Ellis and David Kyte, who bought the building as part of a plan to convert it into residential and commercial properties.
Upon discovering the work, they decided to restore it so that the public could enjoy it once more. This involved cutting out the wall so it could be sent for restoration works, which took 16 weeks by a specialist in Carlisle.
The work, valued at £1.25 million and thought to be the only remaining version of the image, has now been returned to its original home. It is now secured to the floor in a reinforced case in the exact position that it was over a decade ago.