Yevgeny Adamov has denied the charges against him

The US accuses Mr Adamov of embezzling up to $9m (£5.2m) it gave to improve security at Russian nuclear facilities.

Moscow filed its own extradition request shortly after the US.

Mr Adamov, who was held on a US warrant in Bern in May, will now face charges in Russia of embezzling $17m (£9.8m).

Russia was fighting for Mr Adamov to be returned for fear that his detailed knowledge of the country's nuclear weapons programme could fall into US hands.

The nuclear physicist, who was Russia's atomic energy minister from 1998 to 2001, accepts his extradition to his homeland but continues to deny the charges.

Mr Adamov was flown out of Zurich airport late on Friday aboard a specially chartered Russian jet, the Swiss justice ministry said.