Oil has made Russia's business elite rich

The Russian prosecutor's office said it had opened an investigation into the tax position of several oil companies, including Yukos, the country's largest single company.

The probe came in response to a request for more information on the oil companies' tax payments from Mikhail Buger, a pro-government parliamentary deputy.

Russian news agency Interfax quoted Mr Buger as saying that Yukos paid only the equivalent of $2.9m (�1.75m) in taxes last year, a small fraction of the $700m it paid to shareholders in dividends.

A Yukos spokesman described the allegation as "nonsense," saying the company had in fact paid $3.3bn in 2002.

Warning shot

The inquiry into Yukos' tax affairs follows the arrest last week of Platon Lebedev, the billionaire chairman of finance group Menatep, which owns 61% of the oil giant's shares.

Mr Lebedev was detained in connection with the alleged embezzlement of $280m's worth of shares in a state-owned fertilizer company in 1994, when Russia's chaotic privatisation programme was at its height.

State prosecutors also interviewed Yukos chairman Mikhail Khodorkovsky when Mr Lebedev was arrested.

Analysts believe the authorities' sudden close interest in Yukos' affairs is intended as a warning to Russia' super-rich elite to stay out of politics ahead of parliamentary elections in December, and a presidential contest next year.

Mr Khodorkovsky, Russia's richest man, aligned himself earlier this year with Russia' liberal opposition.