Up for grabs - the Caravaggio the burglars left behind

Judith and Holofernes has gone on display in London. Photo / AP

When burglars raided a rambling farmhouse in Toulouse, they made off with some Art Deco perfume bottles but ignored the dusty old painting propped against the wall.

It is a decision they may now regret. That painting is being sold as a lost work of Caravaggio, with an estimate of up to £129 million ($251m).

Judith and Holofernes, which will be auctioned in France on June 27, went on display in London yesterday. Remarkably, it will be sold without reserve — meaning a buyer could pick up the bargain of a lifetime. But there is a catch.

Art historians are divided on whether it is a genuine Caravaggio, painted in 1607, or a very good copy.

"The poor buyer of this picture will not enjoy it," admitted Eric Turquin, the Parisian dealer behind the sale. He fears the new owner will be overwhelmed by letters saying it is a fake.

Nevertheless, Turquin believes it to be genuine. He cited letters from an agent who was buying Caravaggio pictures on behalf of a duke in 1607, reporting from the Italian artist's studio that he had produced a beautiful painting of "three figures, half-length".

Other documents follow it to Antwerp, where it disappeared from the record until it was found unnoticed in the Toulouse farmhouse in 2014, dirty and water-damaged.

Turquin said: "The picture has an extraordinary energy. This cannot be the work of a copyist, or if it's a copyist he is a genius."

A Caravaggio has sold at auction only once before as all but two of the 65 known works are in public collections or churches. The painting, which is on display at the Colnaghi gallery in Mayfair until March 9, depicts the biblical tale of Judith, a widow who beheads an enemy general. Caravaggio had produced a similar scene in an earlier work.