Pablo Picasso's Bust of a Woman in a Flowery Hat, unseen for 80 years, has been unveiled in Paris and is expected to fetch an estimated at eight million euros ($A14 million) at auction.
The 80cm x 60cm oil painting depicting Dora Maar, Picasso's best-known muse, had been in a private collection since it was bought in 1944. It was presented at the Hotel Drouot in Paris, where it will be auctioned on October 24.
"Unknown to the public and never exhibited except in the Spanish master's studio in Paris during the German occupation, this painting is truly exceptional and marks a turning point in the history of art and in Picasso's work," said Agnes Sévestre-Barbe, an expert on Picasso, at the unveiling.
Inspired by both naturalism and cubism, the canvas depicts Marr, overcome with grief but with a harmonious face, wearing a flowery, colourful hat, at the moment when Picasso leaves her for a younger woman, Françoise Gilot.
Picasso and Dora Marr were together from 1935 to 1943. At the time, Picasso was in a relationship with Marie-Thérèse Walter, with whom he had a daughter Maya, that continued during his years with Maar.
The pair's tumultuous nine-year affair is credited by some critics with helping Picasso rekindle his creative spark.
The authenticity of the painting was confirmed by the Picasso Foundation and was known to experts only in a black and white photograph taken shortly before it was sold.
The record sale for one of Picasso's works is The Women of Algiers (Version O), a 1955 oil painting which sold for $US179.4 million at Christie's in New York in 2015.
