The Federal Security Service on Thursday said that on March 12 officers had detained TNK-BP's Ilya Zaslavsky, along with his brother Alexander, who has links with the British Council, for "illegally gathering secret commercial information for the benefit of several foreign oil and gas companies, in order to give them advantages over Russian competitors."
The British Council, the U.K. Embassy's cultural arm, said Ilya Zaslavsky was not on its staff but was a member of the embassy's alumni club for foreign graduates of British universities. The British Council, whose regional offices in Russia were closed down earlier this year over alleged tax violations, subsequently voiced its concern over the arrests.
However, Russia denied there was a connection between the two matters.
"There is no sense in looking for a connection between these two completely separate cases," Andrei Krivtsov, a deputy head of the Foreign Ministry's information and press department, said.
TNK-BP's stock fell 4.5% on the RTS exchange after the news.
Charges were brought against the Zaslavsky brothers on March 18.
On Wednesday, police seized documents from the central office of the Russian-British venture TNK-BP, one of the largest crude producers in Russia. The Moscow office of British oil major BP was also raided by police.
Security officials said copies of official documents, papers on oil and gas production believed to contain commercial secrets, as well as ID cards belonging to foreign military organizations and to the CIA were found during the searches.
Despite Russia's denial that the two cases are unrelated, the arrests have the potential to further worsen Russian-British relations, already strained following the murder of Russian security service defector Alexander Litvinenko in November 2006 in London, and more recently by the closure of British Council offices.