A final decision on where Alexander Vinnik is extradited to now lies with the Greek justice minister, who steps in to resolve competing requests.
Vinnik, the alleged mastermind of a $4 billion bitcoin laundering ring, is one of seven Russians arrested or indicted worldwide this year on U.S. cybercrime charges.
U.S. authorities accuse him of running BTC-e -- a digital currency exchange used to trade bitcoin -- to facilitate crimes ranging from computer hacking to drug trafficking since 2011.
He denies the charges against him and says he was a technical consultant to BTC-e and not its operator.
Since Vinnik’s arrest in a village in northern Greece in July, Moscow has also requested he be returned home, as it has done before with other nationals wanted by the United States.
Vinnik has agreed to be returned to Russia, where he is wanted on lesser fraud charges amounting to 10,000 euros, but he appealed to the Greek Supreme Court against a ruling that he be extradited to the United States. The Supreme Court rejected his appeal on Wednesday.
Bitcoin was the first digital currency to successfully use cryptography to keep transactions secure and anonymous, making it difficult to subject them to conventional financial regulations.
The price of bitcoin has soared this year and hit another all-time high on Tuesday, two days after the launch of the first bitcoin futures contract on a U.S. exchange.
Reporting by Constantinos Georgizas; Writing by Karolina Tagaris; Editing by Hugh Lawson