Currency plunge ... a file picture of a money exchange employee changing currency rates on an advertising board in Moscow after a previous devaluation of the rouble. Source: AFP

“This decision is aimed at limiting substantially increased rouble depreciation risks and inflation risks,” the central bank said in a statement posted on its website.

EARLIER: Russia losing up to $162 billion per year because of sanctions

EARLIER: Russian economy slows after sanctions

The rouble on Monday suffered a mini-crash, falling by 9.5 per cent in a single day despite repeated interventions by the central bank, with the latest apparently taking effect on Monday afternoon.

The slide came as the bank warned the low oil price could trigger a contraction of nearly five per cent next year and as tensions surged with the US over the Ukraine crisis.

A dramatically higher interest rate — which was set at 5.5 per cent at the beginning of the year — now threatens to further strangle the economy.

Trouble with the rouble ... this file picture a bank teller holding Russian rouble banknotes. Source: AP

The rouble broke through the level of 64 to the US dollar and 78 to the euro for the first time even though the Bank of Russia has already spent about $US6 billion ($A6.49 billion) so far this month to slow the currency’s slide.

Having lost over 49 per cent of its value against the US dollar this year, the rouble’s slide is now worse than the 48 per cent of the hryvnia in Ukraine, which is fighting a war and is on the brink of bankruptcy.

Russia’s support of rebels in eastern Ukraine and its annexation of Crimea brought on Western sanctions that gave the rouble its first knock earlier this year.

However the heart of the problem is plunging oil prices.

Half of Russia’s revenues come from oil and gas, and the drop in the price of crude oil by half in the past six months has dealt a body blow to the country’s finances and Russians’ confidence in the rouble.