German prosecutors have filed a motion to seize more than €720mn held in the Frankfurt bank account of a Russian financial institution under sanctions, the first time they have moved to confiscate Russian assets rather than just freeze them.

If successful, it would mark a big step-up in international efforts to enforce anti-Russian sanctions. Previously, Germany has only frozen the assets of individuals and firms under sanctions, including yachts and real estate. But if prosecutors succeed in their motion, the funds could be absorbed into the federal budget.

Authorities have not confirmed how they would use the cash or whether it would be funnelled to Ukraine, a plan being explored in the west for Russia’s central bank assets if they are eventually seized.