Mikhail Khodorkovsky is hardly a household name in the United States, but much of the world considers him Russia's most prominent political prisoner since Aleksandr Solzhenitsyn.

Once Russia's richest man, the 47-year-old oligarch is a prisoner near the Finnish border. Before his fall he brought modern Western business practices to Yukos Oil Co., the nation's top petroleum producer. He also has applied progressive thinking to issues of corporate social responsibility and outspokenly promotes government respect for democratic values, human rights and an independent judiciary.

The documentary "Khodorkovsky" argues that making such reform-minded statements in an authoritarian state is a quick way to get oneself long-term occupancy of a private room with a large and well-armed security staff. That's where he languishes today since being jailed without trial in 2003 for tax evasion. On Dec. 30 he was sentenced to six more years as prosecutors inventively discovered new charges, including an alleged scheme to steal 218 million tons of oil. If the getaway vehicle for that caper was a tanker train it would stretch around the world three times.

The documentary suggests that Khodorkovsky's imprisonment is a gambit by the Kremlin, which detests dissidents, and more specifically by Vladimir Putin, formidable former president and incumbent prime minister of Russia, who saw the handsome young billionaire as a potential political rival.

Indeed the filmed segments where Khodorkovsky publicly puts the screws to Putin about official corruption makes the leader look like a strutting thug.

But you can't always go by appearances. The film, directed by German documentarian Cyril Tuschi, features many sympathetic interviews with the oil magnate's family members, supporters and former colleagues, but it feels incomplete.

We don't learn that in May the European Court of Human Rights rejected his contention that the Russian charges of financial wrongdoing against him were politically motivated. There's no one from the current Russian power elite commenting on the affair, no deep look into the wild and woolly banking operation Khodorkovsky ran before his move into big oil. The murky "insiders' club" process through which he bought Russia's largest oil producer (a $15 billion value) for just $300 million goes unexplained. The murder of a provincial mayor who was a thorn in Khodorkovsky's side gets scant screen time. Navigating a tangled tale such as this is like entering a hall of mirrors. "Khodorkovsky" doesn't do a good enough job of Windexing them.