The head of the British Embassy's economic section was one of four diplomats told to leave Russia in the tit-for-tat diplomatic expulsions that have followed the poisoning of Kremlin critic Alexander Litvinenko in London.
Economic Counsel Andrew Levi is to leave Russia on Sunday, Dow Jones Newswires reported, citing unnamed sources. The report said Levi is one of the four British diplomats sent home in response to Britain's decision to expel four Russian diplomats after Moscow refused to extradite the main suspect in the killing of Litvinenko.
Neither Levi nor his assistant were answering their phones on Thursday.
The embassy press service said it was standard diplomatic practice never to comment on expulsions.
The names of the expelled Russian diplomats have not been made public, so it was unclear whether Russia's expulsion of Levi was a tougher move.
The Moscow Times, the first to report Levi's expulsion, said he had played a major role in negotiations last year over a giant gas project on Russia's Pacific Coast which led to state-controlled gas monopoly Gazrpom buying control from Royal Dutch Shell PLC after months of regulatory pressure.
Gazprom's arrival at the Sakhalin-2 project was seen as part of the Kremlin's push to recapture control of major oil and gas projects.
In June, BP PLC's joint venture in Russia, TNK-BP, agreed to be bought out of the development of another giant gas field by Gazprom. The Kovykta project had also faced considerable pressure from Russia's environmental oversight body.
Despite the cases of Kovykta and Sakhalin-2, economic relations between Russia and Britain are strong. Britain is the second-biggest foreign investor in Russia with a total of US$12 billion invested as of 2006.