VIENNA (AP) -- Dmytro Firtash, one of Ukraine's most influential oligarchs, was under arrest in Vienna and facing possible extradition to the U.S. Thursday, a day after being detained in the Austrian capital on an American warrant charging him with bribery and other offenses.
Austria's Federal Criminal Office declined to identify the suspect in keeping with confidentiality rules. But Firtash's company, Group DF, confirmed his arrest.
The company said Firtash's arrest is not linked to current tensions in Ukraine tensions but to investigations connected to an investment project dating to 2006. The statement said the arrest appeared to be a mistake that "will be resolved in the nearest future."
The criminal office said the 48-year-old was arrested Wednesday night in Vienna without incident and is now being held pending extradition proceedings. The agency said the FBI has been investigating him since 2006.
Firtash was a supporter of fugitive Ukrainian President Viktor Yanukovych and a major player in the sale of billions of dollars in Russian natural gas to Ukraine through RosUkrEnergo, a trading company he co-owns with Russian state gas company Gazprom.
RosUkrEnergo was the sole supplier of Russian gas to Ukraine until 2009, when it was sidelined as part of an agreement struck to resolve a gas dispute that had cut off supplies to Europe for more than two weeks that winter.
In a diplomatic cable sent in November 2008 made public by WikiLeaks, former U.S. Ambassador to Ukraine William B. Taylor called Firtash "one of Ukraine's most wealthy and notorious oligarchs" and suggested that he held ties to Russian organized crime figure Semyon Mogilevich.
In another cable sent in 2010, Taylor wrote that Firtash "acknowledged ties to ... Mogilevich, stating he needed Mogilevich's approval to get into business in the first place."
Tim Ash, an emerging markets analyst with Standard Bank in London, called the arrest a "seismic development," describing Firtash as one of the top two Ukrainian oligarchs in terms of wealth and influence at home and abroad.
In an email, he said Firtash's detention sends a strong message to oligarchs in Russia and other former Soviet republics "that no one is above the law and ... that if they are to do business in (or) with the West, they need to comply with some basic Western values."
For Russia, he said, the message is that the West is ready to sanction top pro-Moscow magnates unless the Kremlin moderates its policy toward Ukraine and in particular on the status of Crimea. With Moscow's backing, the Crimean peninsula is holding a referendum this weekend on splitting from Ukraine and joining up with Russia.
Associated Press writers Maria Danilova in Kiev, Ukraine, Lynn Berry in Moscow and David Rising in Berlin contributed to this report.
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