LONDON, Reuters -A derivatives panel ruled Wednesday that Russia may be in default following it failing to pay a due date of April 4, in U.S. Dollars on two sovereign bonds. This brings a possible payout for billions in default insurance a step closer.

After Moscow paid in roubles instead of dollars, the credit derivatives determinations panel stated that there had been a “potential fail to pay”.

Moscow claimed it needed to make the payment by roubles because the U.S. Treasury had prevented Russia using any frozen foreign currency reserves in order to service its debt. Moscow is allowed a grace period of 30 days for the $649million payment, which will end on May 4.

Since the Russian Bolshevik Revolution of 1917, Russia has not fallen behind on its foreign debt.

This committee’s ruling could result in a payment on credit default swaps (CDS), which are instruments that offer investors insurance against specific risks. In this instance, Russia defaulting on its sovereign bonds.

JPMorgan, an investment bank, estimated that Russia CDS net notional Russia had $3.43 trillion at the moment. This includes $2.48 billion for single names and the rest from CDS indexes.

Members of major investment banks such as Bank of America (NYSE;), Citibank (NYSE:), JPMorgan Chase, JPMorgan Chase, (NYSE:) or PIMCO make up the committee that decides on whether Russian sovereign debt credit default swaps may be paid.