The 400-year-old work, which was found by accident in 2014 in an attic of a house in Toulouse, is thought to have been painted by Italian master Caravaggio, according to Old Masters expert Eric Turquin, who has been studying it for the past two years.
The amazing find was discovered in a sealed-off part of the attic space, which had to be accessed in order to repair a leak.
Named "Judith Beheading Holofernes," the painting represents the biblical figure Judith decapitating Holofernes, an Assyrian general. According to the Book of Judith (included in Roman Catholic and Eastern Orthodox scriptures) she went in supplication to the general's tent while his forces besieged her city, then beheaded him.
French authorities have slapped an export ban on the painting, which experts value at around 120 million euros ($136 million) citing its importance to the art world and a need to "fully investigate" it.
"The rediscovery of an original masterpiece by Caravaggio is a great event," Turquin said. The painting "should be considered by far the most important canvas recovered in the last twenty years, from one of the geniuses."
If authenticated, the painting would stand as a particularly grisly example of Caravaggio's work, but by no means out of character.
The painter, who was active around the turn of the 17th century, repeatedly explored violent themes in his biblical work -- even decapitation, such as in his 1608 work "The Beheading of Saint John the Baptist
," and "David with the Head of Goliath
of Caravaggio's "Judith" exists, and was painted around 1599.
The new discovery was painted sometime between 1600 and 1610, experts believe.
Another Caravaggio expert, Nicola Spinoza, said in an assessment, that "One has to recognize the canvas in question as a true original of the Lombard master, almost certainly identifiable, even if we do not have any tangible or irrefutable proof," French media outlet AFP reported
Other art historians have pegged a Caravaggio contemporary -- and imitator -- Louis Finson, as the painter of the work, but Turquin believes it is the real deal, saying that the painting's "energy" is a telling sign that the work is an original Caravaggio, not an imitation.
Turquin has said that there is a likelihood that the true provenance of the painting will never be proved beyond doubt.