Russian authorities in second raid on BP's Moscow offices

The Russian premises of the oil giant BP were searched yesterday for the second time in recent months, prompting renewed fears of a campaign to pressure shareholders into selling their stakes to a state-controlled company. Additionally, the Russian Interior Ministry said it was investigating back-tax claims against two units linked to the company.

A company spokesman, Vladimir Buyanov, said he believed the FSB, the Russian security services, were behind the search. The FSB refused to comment. Mr Buyanov said the company was co-operating with the search and staff had continued to work.

Analysts have long suspected state energy giant Gazprom is keen to muscle in on BP's Russian operation, TNK-BP, which is a joint venture between BP and a group of Russian billionaires including Viktor Vekselberg and Mikhail Fridman. The company is the third biggest oil producer in Russia and one of the 10 biggest private oil companies in the world.

Reports suggest that back-tax claims for 2002-2003 could amount to more than £20m. The company paid $1.4bn (£711m) in back taxes in 2006.

Yesterday's search is the second time the company has been investigated recently. In March, the offices of BP and TNK-BP were searched. The FSB accused a TNK-BP employee and his brother of industrial espionage, saying they were passing on secret information to foreign oil companies to give them a competitive edge over Russian companies. Ilya Zaslavsky, a Russian national who also holds a US passport and works for the company, was arrested with his brother Alexander who ran an alumni project for the British Council in Russia. The Russian authorities had shortly before insisted Britain close British Council offices outside Moscow.

At the end of March, 148 foreign employees of TNK-BP were withdrawn from Russia, after authorities accused them of violating visa regulations. A minority shareholder is also dragging TNK-BP through the courts, accusing it of harming the company's interests by hiring foreign specialists.

TNK-BP has already been pressured into selling its stake in the vast Kovykta gas field to Gazprom, and last month the business paper Vedomosti quoted sources inside Gazprom saying there was a deal to sell a controlling stake in the company to the state energy giant for $20bn by the end of the year.