MOSCOW: Russia`s internal security agency has disclosed the arrest of two Russian-Americans for their alleged involvement in economic espionage, a day after the raids on the offices of British oil major BP here.

The Federalnaya Sluzhba Bezopasnosti (FSB), country`s federal security service said that, On March 12 it detained Ilya Zaslavsky, an employee of the British Petroleums venture in the country TNK-BP, along with his brother Alexander, who has links with the British Council.

The agency claimed that the duo was "illegally gathering secret commercial information for the benefit of several foreign oil and gas companies, in order to give them advantages over Russian competitors."

British Council, already in the eye of controversy over alleged tax violations, said Ilya Zaslavsky was not its employee but was an important partner as a member of its embassy`s alumni club for Russian graduates of British universities.

The Moscow office of British oil major BP was also raided by police. TNK-BP`s stock fell 4.5 percent on the local RTS exchange after the news.