Russia’s largest oil producer, battered by a gigantic overdue back taxes bill, says it may have to halt its main production units within a few days because of a bailiffs’ order, the Interfax news agency reported in Moscow.

Russia’s richest man, ex-Yukos CEO Mikhail Khodorkovsky, has pleaded not guilty to a raft of charges that could jail him for 10 years, while authorities tightened the grip on the beleaguered oil company’s key production assets.