Austrian authorities have warned that the legal decision could encourage other wanted figures to seek shelter in Austria.
The United States has sought Firtash's extradition on charges that he allegedly paid bribes to officials in India to secure titanium mining licences in 2006.
On Wednesday an Austrian appeals court said the prosecution's latest appeal against a 2024 court decision rejecting Firtash's extradition was "inadmissible" because it was filed too late. It added that its decision was legally binding and thus final.
That 2024 ruling, obtained by AFP on Friday, however said Firtash could not be extradited because Minsk granted him diplomatic immunity in 2021.
According to the document, Firtash represents Belarus at the UN Industrial Development Organization (UNIDO), which seeks to promote inclusive and sustainable industrial development.
The court "assumes" that Firtash "has enjoyed absolute immunity... since notification of this function...(to authorities), which also includes criminal jurisdiction," the 2024 ruling said.
"After examining the legal situation, the court also assumes that the Republic of Austria, as the host state, has no influence on this immunity," it added.
The Austrian judge's ruling also dismissed warnings by Austrian authorities that they do not recognise Firtash's diplomatic accreditation.
Authorities had expressed fears that the legal opinion represented by the court would "soon make Austria the most popular international refuge for millionaire fraudsters, bank robbers, mafia and drug bosses, tax evaders and other individuals".
Contacted by AFP, Firtash's spokesperson said he was "not in a position to comment" on the matter.
Firtash has been unable to leave Austria since 2014 due to an international arrest warrant issued by the United States.
An ex-ally of Ukraine's ousted pro-Russian president Viktor Yanukovych, Firtash made his fortune importing gas to Ukraine from Russia and Central Asia in collaboration with Russian gas giant Gazprom.
He is already the target of British and Ukrainian sanctions.
The 60-year-old has denied all wrongdoing, arguing that the charges brought against him are politically motivated.
Comments