ZURICH (Reuters) – Swiss customs officials are looking into the import of 3.1 tonnes of Russian gold in May to see whether the deals via Britain might have violated sanctions imposed on Russians over Moscow’s invasion of Ukraine, the government said on Friday.

Customs data on Tuesday showed Switzerland imported around $200 million worth of gold from Russia in May, the first imports since the Kremlin sent troops into Ukraine in February.

Switzerland is one of the world’s biggest refining and transit centres for gold, and Russia is one of the biggest bullion producers.

The Swiss Federal Office of Customs and Border Security said in a statement it could not for legal reasons say who imported the gold of Russian origin from the United Kingdom.

“Around three tons of gold originating in Russia and worth CHF 194 million ($202 million) were imported from the United Kingdom to Switzerland. The BAZG (Federal Office of Customs and Border Security) is checking the affected imports with regard to the applicable sanctions,” the BAZG said in a statement posted on the government’s website.

Switzerland has adopted practically all European Union sanctions against Russian companies and individuals.

Importing Russian gold to Switzerland is not prohibited, but the export of gold to Russia is banned.

All bars produced by Russian refineries after March 7, 2022 may no longer be traded in Switzerland. In principle, however, bars produced by Russian refineries before March 7, 2022 can continue to be traded, the office said.

There are basically no restrictions for trading gold in other forms such as jewellery and gold coins.

($1 = 0.9622 Swiss francs)

(Reporting by Michael Shields; Editing by Hugh Lawson)