Ukrainian oligarch arrested in Vienna at FBI's request

An Ukrainian oligarch has been arrested in Vienna this week at the request of US authorities, Austrian government said.

Dmytro Firtash, 48, one of Ukraine's richest men, has close links to Russia through his involvement in the gas, chemicals, media and banking sectors.

He is said to have substantial political influence, notably during the administration of recently ousted, Moscow-backed President Viktor Yanukovich.

The Federal Criminal Office said Mr Firtash had been under investigation by the U.S. Federal Bureau of Investigation since 2006.