Doubts have been cast on the authenticity of a painting, which police in Iraq claim is by Picasso.
The painting, called The Naked Woman, was seized by police south of Baghdad, after a man allegedly tried to sell it for $450,000 (£275,800).
Police said the painting appeared to have been stolen from Kuwait during Iraq's 1990 invasion of the country.
But no record of the painting has been found, leading the art world to doubt it is a genuine Picasso.
Police have said the painting bears Picasso's signature, but the folded canvas has a label on the back printed with several misspellings.
It claims the painting was sold by "the louvre" to "the museum of kuwait" with the words Louvre and Kuwait printed in lower case.
There are also several stamps bearing the name of the Louvre Museum in Paris.
But an official at the Louvre told the Associated Press agency that it has never had a Picasso in its collection and does not sell its works because they are government property.
The Art Loss Registry, based in London, said it has no record of any paintings missing from the Kuwait National Museum.
The Picasso Museum in Paris and France's national museum were also searching their archives for signs of the painting.
Iraqi police seized the painting on Tuesday during a raid on a house near Hillah, about 60 miles (95 km) south of Baghdad.
A judge in Hillah, Aqeel al-Janabi, said the painting will be sent to Baghdad after an investigation.
In a video released by the police, the man detained for trying to sell it, 33-year-old Maitham al-Issawi, said it belonged to his father, who gave it to him before his death.
His father was an army officer who took part in the invasion of Kuwait, which led to the Gulf War.