The rouble fell back on Wednesday, sinking to new record lows against the dollar and the euro.
Tuesday’s rise in the Russian currency proved short-lived, with early trading seeing the rouble fall to 54.82 against the dollar and 67.82 to the euro.
The rouble has lost more than 40% against the dollar and 60% against the euro since the start of the year.
Western sanctions against Russia over Ukraine and the fall in oil prices are hurting the economy.
A decision by the oil producers’ group Opec not to rein in production – which would have bolstered crude prices – sparked a big fall in the rouble. The currency dropped by 9% on Monday – its biggest one-day decline since 1998.
Oil and gas revenues are the biggest single source of revenues for Moscow.
On Monday, Russia’s central bank spent about $700m to support the currency, according to official data.
There were unconfirmed reports on Wednesday that the bank was again intervening to prop up the rouble.
“Without doubt, the central bank is selling (foreign currency),” according to an unnamed trader cited by the Reuters news agency.
The bank indicated in early November that interventions would be less frequent as part of a plan to let it float freely on the currency markets.