The King is among the victims of art theft in France. A diamond­-encrusted snuffbox from the Royal Coll­ection, lent to the Cognacq-Jay museum in Paris for an exhibition last year, was among seven items of “great historic and heritage value” recently stolen.

None have been recovered and ­officials worry the 18th-century snuffbox might never be. They fear it may have been taken not for its beauty or cultural importance but because it ­contained gold that could be melted down and sold.

The practice is increasingly common. This week, for instance, thieves stole six gold nuggets worth €600,000 from the National Museum of Natural History, also in the capital. Having used an angle grinder to get into the museum in the early hours, they cut open the ­display cabinet with a blowtorch and left with the large nuggets, which dated from the 18th and 19th centuries.

Ornate jeweled snuff box.

The Fabrique Royale snuff box, encrusted with nearly 3,000 diamonds, was on loan from the Royal Collection

ROYAL COLLECTION TRUS

“There’s almost no chance that the nuggets will be found in their original state,” Emmanuel Skoulios, the museum’s director, said. “They have without doubt already been melted and perhaps even sold.”

The past year has seen a spate of high-profile thefts in French museums. A day after robbers used axes and baseball bats to smash display cases in front of visitors during Cognacq-Jay’s Pocket Luxury exhibition, an armed gang broke into the Hiéron museum of ­religious art at Paray­-le-Monial in Burgundy. They fired gunshots before taking statues from an early 20th-century work by Joseph Chaumet, the celebrated goldsmith and jeweller. The work, classified as a national ­treasure, was valued at up to €7 million.

The thefts have led to fears that the museums are particularly vulnerable to a wave of art thieves. But this is misleading­. The culture ministry has a specialist police unit dedicated to helping protect artworks worth millions to hundreds of millions of euros. It has ­established cutting-edge technology including ­facial recognition and heat-seeking cameras. The measures are proving effective, at least up to a point.

Gold and other mineral specimens on display at the National Museum of Natural History in Paris.

Gold nuggets worth €600,000 were stolen from the National Museum of Natural History in Paris

ALAMY

Between 2011 and 2018 there were 25 such thefts and attempted thefts a year on average, according to the unit. Between 2019 and last year the average was 13.

A culture ministry source said: “The question of security is important and we are more and more attentive to this question — and this is paying off.”

Yet if total thefts are ­declining, officials have noted an ­increase in those involving artworks targeted for their raw materials, not cultural value. “That’s always existed but it’s true that for the past two or three years, we are seeing an increase in this phenomenon,” the source said.

Vernon Rapley, a British museum security consultant, said the trend was not just limited to France.

In July three men were jailed for up to 11 years for stealing hundreds of ancient gold coins from the Celtic and Roman Museum in the Bavarian town of Manching in Germany in 2022. The court in Ingolstadt was told that the coins were still missing but police had found lumps of gold in the possession of one of the thieves, leading detectives to conclude the bounty was melted down.

Smashed display case at a press conference.

A display case was smashed to steal coins from the Celtic and Roman Museum in Manching, Germany, in 2022

PETER KNEFFEL/DPA/ALAMY

Rapley said that many art thefts were carried out by international networks with no great art expertise. “They do other stuff like drugs and other types of burglary,” he said. “The thing is, what can the criminals do with the [bounty]? Most of them cannot sell art.”

Many conclude it is easier to take and sell works that contain precious metals.

The trend is of concern to French ­officials. “If the theft is for the artwork itself, you can always hope to recover it,” the culture ministry source said. “Thieves who are only interested in the weight of the metal are going to melt it down, and that is a considerable loss.”