Nikolai Vasilyev, who led the team from the St Petersburg Mining University for the Vostok breakthrough last week, insisted that "absolutely nothing fell into the lake".

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Zenit's most high-profile supporter is new Russian president Dmitry Medvedev, who trained as a lawyer in the city and was once an assistant professor at St Petersburg State University.

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Ellen Podgor, an expert in white-collar crime at Stetson University in St Petersburg, Florida, reckons that Siemens confessed all not to minimise the fine it had to pay but to avoid being barred from business with the American government.

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Ella Paneyakh, a sociologist and legal expert at Russia's European University in St Petersburg, said the case illustrated how in President Vladimir Putin's Russia "they are getting very creative, interpreting the law very literally, in a way which does not correspond to the spirit of the law".

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He comes from Mr Putin's native St Petersburg and studied law at the same university.

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But he did broadly align himself with economic reformers and democrats, such as his old university mentor Anatoly Sobchak, who became St Petersburg's mayor in 1991 (and who died last month).

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On returning to St Petersburg in 1990, Mr Putin spent a year as a university bureaucrat, then moved into city government, trying to woo foreign investors.

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