Jailed Russian oil tycoon Mikhail Khodorkovsky on Tuesday ridiculed charges that he stole $30 billion of oil from his own company, beginning his defence in a trial that could keep him in prison for another 22 years, Reuters reported. Khodorkovsky, once Russia's richest man, was arrested in 2003 after falling foul of the Kremlin under Vladimir Putin, and is serving an eight-year sentence for tax evasion. -- SPA