For 123 years, it had been assumed the earliest version of Edvard Munch's masterpiece was soiled by bird droppings - but now the truth is revealed.
Munch's expressionist masterpiece 'The Scream' features a tortured figure, frozen in time with a blazing orange skyline behind, the Mirror reported.
The artist painted four versions between 1893 and 1910, but the most renowned is that found in the Norwegian National Museum.
However, it differs from the other versions in that it features a mysterious white smudge near the central figure's right shoulder.
Photographs from the late 19th Century show Munch often worked outside in the snow, keeping his paintings barely sheltered by a wooden shed. Another was that Munch, or someone else, simply dropped a splash of white paint by accident.
But following painstaking research, a team of scientists led by Dr. Geert Van der Snickt of the University of Antwerp have uncovered the truth.
The white smudge was caused by wax, probably dripped from a candle in Munch's studio onto the painting.
Researchers analyzed The Scream' using a machine they developed themselves called a 'Macro X-ray fluorescence scanner'.
The scans immediately ruled out paint as no pigments or calcium was detected. The team then took a micro sample of the white spot and sent it for analysis in Hamburg.
PhD student Frederik Vanmeert said: "I immediately recognized the diffraction pattern of wax as I encountered this material several times upon measuring paintings."
In the past, artists often used bees wax or a similar material on fragile paintings to stop paint from flaking or to attach a new canvas to the back of a degraded old one.
But in the case of 'The Scream', it is more likely that the white spots are in fact splatters of molten wax that accidentally dripped from a candle in Munch's studio.
The fourth version (pastel, 1895) was sold for $120 million at Sotheby's Impressionist and Modern Art auction in 2012. It is the fourth highest nominal price paid for a painting at the auction.
