The former oligarch has been released by Vladimir Putin – and few know how much remains of his $15bn oil fortune

When secret service personnel in black combat fatigues stormed Mikhail Khodorkovsky'sprivate jet at the remote Siberian Tolmachevo airport in 2003, the oil tycoon was said to be worth $15bn (£10bn). By the time he was behind bars and his business empire began to be systematically dismantled, that fortune was said to have plunged to a little over $2bn.

Now some believe he is reduced to a few million dollars – but no one really knows how much he stashed away in Swiss or other bank accounts before his commercial and political life imploded after falling foul of Vladimir Putin. It would be an unusual oligarch who had not spread part of his colossal holdings in a variety of places, given the unpredictable nature of Russian politics and business.

Khodorkovsky's nemesis, Putin, himself is reported by German newspaper Die Welt to have a fortune of more than $72bn, which, if true, can be expected to be partly held outside of his homeland. The bulk of the Khodorkovsky personal pile of $15bn was estimated by US business magazine, Forbes, to be held in the Yukos petroleum empire he built up from 1995.

The former young communist and trained chemist had bought into the oil group through the Bank Menatap business he had created with partners six years before. Under a highly controversial privatisation process triggered by the government of Boris Yeltsin, Menatap bought a 78% stake in Yukos for $350m. Two years later, Yukos was listed on the stock market with a value of $9bn.

The oil business expanded aggressively, sometimes by barging Western companies out of the way in a style that would have been unacceptable outside of Russia.

But Khodorkovsky soon realised the way to take on the biggest global players such as BP and Exxon was to attract foreign investment, and he did so by introducing unprecedented transparency to the Yukos accounts, including an admission that he was the controlling shareholder.

After his arrest the Yukos group was broken up and sold off, with many of its oil fields ending up in the hands of its smaller rival, now the giant Rosneft. The British group BP now owns 20% of Rosneft, while Khodorkovsky's lawyers continue to challenge the original transfer of Yukos assets in court. After his release, Khodorkovsky may believe they hold the key to restoring his status as the 16th richest man in the world.

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