The only privately-owned version of Edvard Munch's classic masterpiece The Scream has gone on show in London for the first time before it is sold at auction in New York.
The famous picture is on display at Sotheby's in the capital for a week and is expected to fetch 80 million US dollars (£50.4 million) or more at the Impressionist and Modern Art Evening Sale in New York on May 2.
The pastel work, which features a haunted figure in front of a red backdrop, is one of the most recognisable images in the world.
If the piece fetches its estimated value it will be one of the most expensive art works to be sold at auction, alongside Picasso's Nude, Green Leaves and Bust, which holds the current record after it sold for 106 million US dollars (£66.4 million) at Christie's in New York in May 2010.
The Scream up for auction is one of four versions created by Munch and is privately owned by Norwegian businessman Petter Olsen whose father was a friend and patron of the artist.
The Munch Museum in Oslo holds two versions of The Scream and the third is displayed at The National Gallery of Norway.
The Scream for sale was created in 1895 and is the only version with a frame hand-painted by Munch which includes a poem explaining his inspiration for the piece.
It is also the only version in which one of the two figures in the background turns to look outward onto the cityscape. Owner Petter Olsen said: "I have lived with this work all my life, and its power and energy have only increased with time.
"Now, however, I feel the moment has come to offer the rest of the world a chance to own and appreciate this remarkable work, which is the only version of The Scream not in the collection of a Norwegian museum.
"My father Thomas Olsen was a friend of Munch, and acquired The Scream as well as many other works by the artist. He hoped that his collection would further Munch's international renown by lending to exhibitions abroad."
Mr Olsen said the proceeds from the sale will go toward the establishment of a new museum, art centre and hotel on his farm Ramme Gaard at Hvitstenm where his family's relationship with the artist began.
The museum will open in 2013, the 150-year anniversary of the artist's birth.
Philip Hook, senior director at Sotheby's Impressionist and modern art department, said: "This is the only one of the series of four pictures that has this poem by Munch inscribed on the front and it explains a little bit about how the painting came to be executed.
"It tells us that the scream people might have thought was coming from the figure's mouth is not actually him screaming, it's the scream of nature he is hearing through his ears. It's such a powerful image of anxiety and man's alienation.
"We are confident that we will be able to show this icon to as many people as possible. This is the first time this picture has ever been on view in the United Kingdom and it hasn't been on show anywhere since 1979 so it's a very special thing for Sotheby's to be able to show people."
The Scream is the defining image of the Expressionist movement and has been the target of several high-profile art thefts.
In 2004 masked gunmen stole Munch's 1910 version of The Scream as well as his Madonna from the Munch Museum.
Both works were recovered two years later and were back on exhibition in 2008.
From chocolate to graffiti art, The Scream has been replicated in many different ways down the years. Here are some of our favs: