Moscow (AFP) - Net capital outflows from Russia more than doubled in 2014 to $151.5 billion, prompted by the Ukraine crisis and the plunging value of the ruble, according to statistics from the central bank.

Russia in 2013 had already seen its high level of capital flight, a recurring problem for the country, reach $61 billion.

In early December, the central bank estimated that capital flight would amount to $128 billion but it was pushed higher by the ruble's steep plunge at the end of the year on the back of falling oil prices and growing panic as people rushed to exchange their savings.

Just in the fourth quarter of 2014, capital outflows amounted to $72.9 billion, compared to $16.9 billion in the same period a year earlier.

The central bank said that the figure was augmented by foreign currency loans given to banks for the first time to help them withstand the ruble's fall.

"That means $19.8 billion of the capital flight is temporary," it said in a statement sent to AFP on Monday.

Russia's current account surplus, the broadest measure of the country's trade with the rest of the world, reached $56.7 billion in 2014, up from $34.1 billion in 2013.

The capital outflow was accelerated by the payment of debts owed abroad by Russian banks and companies, which have had their access to capital markets cut by sanctions linked to the Ukraine crisis.

"In 2015, it's expected that payments on the external debt will fall, which should have a positive effect on the figures for capital flight," the central bank said.

But economists at Russia's Alfa Bank said capital flight in 2015 could "remain very strong, especially if the central bank continues injecting ruble liquidity into banks."