London: A cleaner at a museum in Germany spotted a `stain` and promptly went to work on the installation. The result was far from flattering as the artwork valued at 690,000 pounds became "impossible to return it to its original state".
The installation that was damaged was by late and famed artist Martin Kippenberger at a museum in Dortmund.
Called "When It Starts Dripping From The Ceiling", it was a tower of wooden slats with a bowl at the bottom. The bowl had been painted brown so that it showed discolouration caused by water, reported telegraph.co.uk.
The cleaning woman thought it was an actual stain and scrubbed it clean.
"It is now impossible to return it to its original state," a museum spokesperson was quoted as saying. The damage was discovered late last month and the work had been on loan to the museum from a private collector.