Finnish customs officials have impounded artworks valued by insurance at over €42 million ($46 million), preventing them from returning to Russia, under European Union sanctions imposed in response to President Vladimir Putin’s invasion of Ukraine.

Finland intercepted three shipments of art at the Vaalimaa border crossing between Finland and Russia last weekend, impounding one vessel. The Finnish Heritage Agency will oversee the storage of the confiscated items until the sanctions are lifted, according to Reuters. The artworks are still Russian property, and are being held as evidence.

A spokesperson for the Russian foreign ministry, Maria Zakharova, confirmed that on April 5, diplomats from the Russian embassy in Finland accompanied the works’ transfer to facilities at the Ateneum state museum in Helsinki. They advised Finnish authorities that breaking the seals on the packaging was “unacceptable.”

“Professionals have been consulted in the moving and storage of the goods,” customs enforcement director Hannu Sinkkonen said at a press conference, reports Agence France-Presse. “We are not going to open the packages.”

The shipments “include works which cannot be valued; they are priceless,” he added..

Giovanni Cariani, Giovane donna con vecchio di profilo (ca. 1515–16). Collection of the State Hermitage Museum, St. Petersburg, Russia.

E.U. sanctions introduced in mid-March prohibit the sale, supply, transfer, or export of luxury goods—including artworks—to Russia, due to the invasion. Authorities say there are 10 people suspected of having violated the sanctions to transport the art.

The works, which include paintings, statues, and antiques, had been on loan to Italy from the collections of the Hermitage and Tsarskoye Selo state museums in St. Petersburg and the State Tretyakov Gallery in Moscow, the Russian ministry of culture told the Russian news agency Moskva. The artworks returning from Japan belong to Moscow’s Pushkin State Museum of Fine Arts.

“The enforcement of sanctions is part of our normal operations and we always direct our controls based on risks. The shipments that have now come under criminal investigation were detected as part of our customary enforcement work,” Sami Rakshit, head of the enforcement department of Finnish Customs, said in a statement.

Titian, Young Woman with Feather Hat (ca. 1536). Collection of the State Hermitage Museum, St. Petersburg, Russia.

In early March, the Hermitage had requested that three Italian institutions return loaned works ahead of schedule. At that time, the Gallerie d’Italia in Milan was exhibiting Antonio Canova’s Psyche Revived by Cupid’s Kiss (1787–93); the Palazzo Reale, also in Milan, had displays of Titian’s Young Woman with Feather Hat (ca. 1536) and Giovanni Cariani’s Giovane donna con vecchio di profilo (1515–16); and Rome’s Fondazione Fendi had Young Woman (1909) by Pablo Picasso on view.

Finland has been strict in enforcing sanctions against Russia, also prohibiting 21 luxury yachts from departing Finnish waters last month amid suspicions that the vessels belong to sanctioned individuals.

“As for the arrested paintings, they will return and pay a penalty,” the Russian State Duma Speaker, Vyacheslav Volodin, said in a statement. “Those who did this in Finland probably do not remember their history well.”

Zakharova, of the Russian foreign ministry, told Artnet News: “Basically, the situation can be described as legal anarchy. We are talking about the seizure, in violation of international law, of artwork owned by the Russian Federation that temporarily was on display abroad under the governmental guarantees of the countries where these items were exhibited on a nonprofit basis and in cooperation with our museums. We are waiting for the Finnish authorities to act with due haste to ensure that all these works are returned to the Russian Federation.”

This week, France agreed to return 200 paintings on loan to Paris’s Fondation Louis Vuitton for the show “The Morozov Collection: Icons of Modern Art” to Russia, despite calls to confiscate the works.