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Profile: Alexei Navalny, Russian opposition leader

30 October 2012 Last updated at 18:41 GMT

The Russian lawyer and anti-corruption campaigner Alexei Navalny recently topped a ballot to elect leaders of the opposition to President Putin.

Lucy Ash profiles the man who came to prominence as a leader during the anti-Putin demonstrations in Moscow last December - the biggest such rallies since the end of the Soviet Union.

Navalny has also been fighting against corruption through a website that invites the public to report suspected cases to the police or prosecutors. One of his tactics was to become a minority shareholder in major Russian oil companies, banks, and ministries to ask awkward questions about holes in state finances - and those holes are huge.

Last year Dmitri Medvedev - then President, now Prime Minister - said that a trillion roubles ($33 billion) disappears annually on government contracts. Navalny's campaign has won him popularity across a wide spectrum of Russian society - including nationalists with far-right connections, and this has unsettled many more liberal supporters.

And in a week when three other opposition activists have been charged with causing mass unrest, does Alexei Navalny have what it takes to challenge the tough man in the Kremlin?

This edition of Profile was first broadcast on BBC Radio 4 on Saturday, 27 October 2012. You can download the programme via the Profile podcast.