Gerashchenko told reporters that the "American justice" can not be bribed.

"There may only be a deal. If Firtash is offered to testify on his corrupt ties in the Russian Federation – and it is no secret that he had reached big deals with Russian leaders on gas supplies and other economic issues -- I think that the Americans will offer Firtash a possibility of remaining a free man in exchange for his testimony against Russian top leadership’s involvement in corruption schemes," said the deputy. Gerashchenko believes that otherwise, Firtash is facing a really long term behind bars in the U.S., as it once happened to Ukraine’s former senior official Pavlo Lazarenko, who was jailed for 14 years for laundering illicit funds.

As UNIAN reported earlier, an Austrian court had ruled Tuesday, February 21, that one of Ukraine's richest men, Dmytro Firtash, should be extradited to the U.S. to face corruption charges.

"(The appeal against the previous ruling) has been granted," the judge told a courtroom packed with journalists and Firtash's family, according to Reuters. "This does not mean that somebody is being pre-judged as guilty, but rather that it will be decided in another country whether they are guilty or innocent."

Read alsoUkrainian journalists find most popular countries for fleeing corrupt officialsA U.S. grand jury indicted Firtash in 2013, along with a member of India's parliament and four others, on suspicion of bribing Indian government officials to gain access to minerals used to make titanium-based products and has long sought his extradition from Austria.