A Geneva court temporarily released a former Kremlin aide, Mr Pavel Borodin, from custody yesterday on bail of $3 million (€3.4 million).
Mr Borodin is accused of money laundering in Switzerland in connection with a $25 million kickbacks scheme involving Kremlin renovations carried out under Mr Boris Yeltsin's presidency.
Two Swiss construction firms, Mabetex and Mercata Trading, which won the contracts, have been linked to the scandal.
Judge Martine Heyer of the Geneva Court of Criminal Appeal told Mr Borodin that he must be available to Swiss justice authorities during the course of their investigation.
Mr Borodin's defence lawyer, Ms Dominique Poncet, welcomed the decision and said the bail will be paid "as quickly as possible".
In Moscow, Ms Eleonore Sergeyeva, a lawyer also representing Mr Borodin, was quoted by Ria-Novosti as saying that the former Kremlin property manager could return to Moscow by the weekend.
Mr Borodin (54) was extradited on Saturday from the United States where he was arrested on a Swiss-issued international arrest warrant in January, and charged a few hours after his arrival. A second charge of belonging to a criminal organisation was dropped yesterday by the court which said there were no elements to back it up.
Pale and looking grave, Mr Borodin, who is currently secretary-general of the Russia-Belarus Union, attended the hearing yesterday but did not address the court.
He was expected to return to the hospital where has been receiving treatment in a high security ward since Monday after complaining of chest pains. "He will return to hospital, he has to be kept under observation," Ms Poncet said.
Russia welcomed the ruling, a government spokesman citing "the principle that a Russian citizen whose guilt is not proven should not remain in prison".
Mr Robert Assael, another of Mr Borodin's Swiss lawyers, said it may be the Russian state which pays the bail, recalling that Ms Poncet had told a court hearing earlier in the week that Russia would pay money to guarantee Mr Borodin did not flee.
If bail is not posted, the court said Mr Borodin will remain in custody for another three months until July 10th.
Russian investigators formally closed their inquiry into the Kremlin scandal last December and have said he has committed no crime.