A Russian bank has got a 6 billion-dollar loan from Chinese banks to finance state oil firm Rosneft's purchase of a core production unit of oil giant Yukos, a top Russian energy official said Tuesday in Moscow.

Without naming the Chinese banks, Russian Finance Minister Alexei Kudrin said Russia's Vnesheconombank borrowed the loan to credit Rosneft for the purchase of Yukos' major subsidiary Yuganskneftegaz, which was put up for auction in December to raise money for the payment of Yukos' multi-billion-dollar back tax bill.

Rosneft had paid 9.4 billion US dollars for the acquisition of Yuganskneftegaz after it purchased Baikalfinansgroup, the previously unknown company that unexpectedly won the bid for Yuganskneftegaz, which produces 60 percent of Yukos' output.

The sale has been considered as a key stage of the year-and-a-half judicial campaign against Yukos. Some critics see the legal process as a Kremlin-inspired political move to dwarf former Yukos CEO Mikhail Khodorkovsky who has allegedly funded political opponents of President Vladimir Putin.