The Channel Island of Jersey says it is freezing assets connected to Russian billionaire Roman Abramovich estimated to be worth over $7 billion.

The Law Offices Department of Jersey, a tax haven long known for drawing large amounts of foreign direct investment, said Wednesday that the assets being targeted were either located in Jersey, or owned by Jersey-incorporated entities.

It said that police also executed a search warrant Tuesday at addresses suspected to be connected to Abramovich’s business activities. It didn’t provide details.

Abramovich, an ally of Russian President Vladimir Putin, has been sanctioned by the U.K. government and the European Union. The 55-year-old tycoon has assumed an unofficial role in the negotiations between Ukraine and Russia aimed at ending the war.

(AP)