A judge in Paris has ordered a French trial for Alexander Vinnik, a Russian suspected of money laundering on the bitcoin exchange BTC-e, also wanted by Washington and Moscow, his lawyer and other sources told AFP.
Vinnik was extradited to France in January from Greece, where he had been arrested on an American warrant in 2017.
Vinnik allegedly operated the BTC-e exchange until his arrest at the northern Greek tourist resort of Halkidiki, which set off a three-way extradition tussle between the United States, France and Russia.
A U.S. indictment accuses him of 21 charges ranging from identity theft and facilitating drug trafficking to money laundering.
French authorities, meanwhile, accuse him of defrauding more than 100 people in six cities between 2016 and 2018.
Vinnik has denied the charges and has sought an extradition to Russia, where he is wanted on lesser fraud charges involving just 9,500 euros ($11,000).
But a judge has ruled that Vinnik will stand trial in France for extortion, aggravated money laundering, criminal association, and fraudulently accessing and modifying data in data processing systems, a source close to the case told AFP.
The victims, according to prosecutors, are individuals, local authorities and companies.
His lawyer, Ariane Zimra, complained that the defence team had not been given a chance to present facts before the decision was taken to order a trial for his client.
BTC-e, founded in 2011, became one of the world's largest and most widely used digital currency exchanges.
But according to the U.S. indictment, BTC-e is also suspected of playing a major role in online extortion and other cyber-crimes.
France opened a probe in 2016 after victims of the "Locky" ransomware filed a complaint.
Investigators said they found evidence to link the software, which blocks and encrypts data and releases it only on payment of a ransom, to Vinnik.
Some 135 million euros are believed to be involved in France.
The U.S. Treasury Department has already fined BTC-e $110 million for "wilfully violating" anti-money laundering laws.
Vinnik himself has been ordered to pay $12 million.