The trial in absentia of Mukhtar Ablyazov, a fugitive banker and Kazakh opposition figure wanted on embezzlement charges by Kazakhstan, Russia and Ukraine began Friday, a court in the Central Asian country said.
"The process began on March 17 at 10.00 (0400 GMT)," a representative of the special inter-district criminal court in oil-rich Kazakhstan's largest city Almaty told AFP by phone.
Ablyazov, a former energy minister and banker in Kazakhstan and his associates are accused of embezzling billions of dollars from BTA bank, once a leading lender in the authoritarian republic.
He has always denied the charges, claiming they are linked to his political opposition to 76-year-old Kazakh leader Nursultan Nazarbayev.
His three alleged accomplices were all facing trial Friday, the court representative confirmed.
Ablyazov, currently based in France, is widely believed to have bankrolled opposition groups and media in Kazakhstan, a republic of 18 million that Nazarbayev has maintained a vice-like grip over since before independence in 1991.
He promised to topple the Kazakh government "in the space of three years" after France's highest administrative authority decided to halt extradition proceedings against him in December.
Ablyazov was set to be extradited to Russia, where he is also wanted on charges connected to alleged corruption at BTA, but the council saw a "political goal" behind Kazakh ally Russia's extradition request.
The banker predicted he "would have been killed" in the space of "one month to a year" had the extradition -- which could have been followed by extradition to Kazakhstan -- gone ahead.
The UN Special Rapporteur on Torture advised France against the extradition, citing a serious risk of torture.
Ablyazov spent more than three years in custody after being arrested by French authorities in the Cote d'Azur region in 2013.