A judge ruled that the proceedings would be held behind closed doors at the request of Russia's Central Bank, which sought to "protect banking secrecy."
The economic situation is likely to worsen as Iran's Central Bank drastically reduced the subsidised exchange rates for dollars it offers to importers and producers.
The Hungarian prime minister strongly condemned a move by the EU to indefinitely immobilise Russian Central Bank assets, widely seen as a way of circumventing a Hungarian veto.
The move would allow EU leaders to work out at a summit next week how to use the tens of billions of euros in Russian Central Bank assets to underwrite a huge loan to help Ukraine in the war.