Transfer of more than $100bn out of US prompts speculation Russia is moving funds out of reach of possible sanctions

Financial markets were on high alert last night over the Ukraine crisis amid speculation that the Kremlin had pulled its vast US treasury bill holdings out of New York.

News that more than $100bn had been shifted out of the US in the past week – at least three times more than at any time since the financial crisis – prompted fears that Russia is preparing for a western backlash in the form of sanctions and is moving its funds to safe havens beyond US influence.

The bills were transferred out of the US central bank's deposit vaults last week, as the Obama administration increased the threat of sanctions in response to the growing crisis in east Ukraine. Last year the most moved in a week was $32bn. Analysts said that if the switch can be credited to Russia, it represents about 80% of the country's holdings in US Treasury bonds.

The Russian central bank is likely to be behind the move, though wealthy Russian business figures are also expected to be concerned that Washington-imposed sanctions will freeze funds they have parked with the US central bank. Alexei Miller, the boss of energy firm Gazprom, and Igor Sechin, who runs oil company Rosneft, are likely to be among the many senior figures in Moscow adversely affected by any targeted sanctions imposed on Russia.

The switch came to light after the US central bank reported that its weekly custody holdings of Treasury bonds – investments it keeps on behalf of outside investors – dropped $105bn for the week ending 12 March to $2.85tn from $2.96tn.