Russia has accused the British Embassy's top trade official in Moscow of espionage, the British Foreign Office confirmed Friday.

The accusation appears likely to worsen Russian-British relations, already strained in part by the continuing fight for control at the TNK-BP oil company, which is jointly owned by the British company and Russian billionaires.

The Interfax news agency, citing a source in Russia's secret services, reported Thursday that the head of the embassy's trade and investment section, Christopher Bowers, was believed to be a senior British intelligence officer.

The British Foreign Office said the accused diplomat was acting head of U.K. Trade and Investment at the embassy and confirmed his name was Chris Bowers.

The former top trade official, Andrew Levi, was one of four British Embassy officials expelled from Moscow last summer.

The expulsions were retaliation for Britain's expulsion of four Russian diplomats after Russia refused to hand over the main suspect in the 2006 poisoning death of Kremlin critic and former Federal Security Service officer Alexander Litvinenko in London.

The new espionage accusation followed a report Monday by the BBC suggesting Russian government involvement in the killing of Litvinenko.

The Federal Security Service and Foreign Ministry both refused to comment Friday.