Later this year, the Louvre in Paris will host an exhibition of masterpieces by the Italian painter Leonardo da Vinci to mark his death 500 years ago in France.
But the work that in recent months has been the intense focus of scrutiny by the media and da Vinci specialists, may not be on show.
In 2017, "Salvator Mundi" was sold at auction by Christie's as a work by da Vinci for a record $450 million.
But it has not been displayed in public since, triggering doubts about its ownership, its whereabouts and its authenticity.
'Nothing by Leonardo'
Many art experts remain unconvinced of the painting's authenticity.
"Certain details are very telling," said Jacques Franck, a specialist in da Vinci's technique, pointing to the poor depiction of a finger and other elements that are "anatomically impossible".
He said that at the time the canvas was painted, da Vinci had his workshop complete certain paintings because he himself had very little time.
Ben Lewis, an art historian who wrote "The Last Leonardo" said London's National Gallery, which exhibited the painting in 2011, had not taken on board the advice of five experts who were sent to authenticate the painting.
Although two of them believed it was authentic, another didn't, and the others were unsure. But the painting was presented at the exhibition as a genuine work by Leonardo da Vinci.
But Diane Modestini, who worked on the restoration of the painting from 2005, said she did not understand the controversy, insisting that "Leonardo da Vinci painted it".
A Christie's spokesman said, "We stand by the thorough research and scholarship that led to the attribution of this painting in 2010. No new discussion or speculation since the 2017 sale at Christie's has caused us to revisit its position."
'Reputation and credibility'
The Louvre says its exhibition, due to open in Paris in the autumn, will bring together "a unique group of artworks that only the Louvre could bring together" in addition to its own outstanding Leonardo collection.
But whether people will be able to draw their own conclusions by actually seeing the "Salvator Mundi" remains to be seen.
Agence France-Presse