The Guardian's Moscow correspondent has been expelled from Russia, in what is believed to be the first removal of a British staff journalist from the country since the end of the cold war.
Luke Harding's forced departure comes after the newspaper's reporting of the WikiLeaks cables, where he reported on allegations that Russia under the rule of Vladimir Putin had become a "virtual mafia state".
The journalist flew back to Moscow at the weekend after a two-month stint reporting on the contents of the leaked US diplomatic cables from London, but was refused entry when his passport was checked on his arrival.
After spending 45 minutes in an airport cell, he was sent back to the UK on the first available plane – with his visa annulled and his passport only returned to him after taking his seat. Harding was given no specific reason for the decision, although an airport security official working for the Federal Border Service, an arm of the FSB intelligence agency, told him: "For you Russia is closed."
The tightly controlled nature of Russian politics means the expulsion is likely to have been ordered at a very senior level, but the British government has so far been unable to find out any more details about the decision.
William Hague, the foreign secretary, contacted his Russian counterpart Sergei Lavrov on Monday afternoon in an effort to establish what had happened. It is understood Lavrov had no explanation to offer, and promised only to look into the matter.
Alan Rusbridger, the Guardian editor-in-chief, said: "This is clearly a very troubling development with serious implications for press freedom, and it is worrying that the Russian government should now kick out reporters of whom they disapprove. Russia's treatment of journalists – both domestic and foreign – is a cause of great concern. We are attempting to establish further details, and are in contact with the Foreign Office."
The last prominent British journalist to be expelled was Sunday Times correspondent Angus Roxburgh, who was kicked out of Russia in 1989 in a "tit for tat" expulsion after Margaret Thatcher asked 11 Russian spies to leave London. He returned a few months later after the fall of communism, working for the BBC.
Harding's expulsion follows several incidents of harassment amid official disapproval of his coverage. He was briefly detained in April 2010 in Ingushetia after a visit to the troubled the Caucasus region. In May he interviewed the Dagestani father of Mariam Sharipova, a suicide bomber who killed 26 people on the Moscow Metro in March 2010.
Although western reporters are not subject to anything like the dangers of some of their Russian counterparts, several of whom have been murdered for delving too deeply into the corruption and mafia nexus at the heart of the Putin state, English-speaking Moscow correspondents are careful about what and how they report.
Sensitive areas include references to the alleged personal wealth built up by Putin, any discussion about corruption that is linked to senior government individuals, or any reporting that implies the Kremlin had any prior knowledge of the plot to kill the former spy Alexander Litvinenko.
In December the Guardian published an article by Harding which reported that Putin was likely to have known about the planned assassination in the opinion of Washington's top diplomat in Europe because of the Russian prime minister's "attention to detail". That report was part of the newspaper's WikiLeaks coverage.
Harding may have further irritated the Russians because other newspapers covering the WikiLeaks diplomatic cables opted to farm out the reporting of their contents relating to the country to correspondents based outside the country. He believed it was appropriate to put his name on the Russian WikiLeaks coverage because the authorities would have believed it was he who wrote the material anyway.
After the cables were first published, Harding co-authored a book, WikiLeaks: Inside Julian Assange's War on Secrecy, revealing the inside story of the publication of the confidential documents.
Harding said: "I didn't go out to Russia with any particular agenda and I'm sad to leave under these circumstances. But I do not think journalists can accept self-censorship."
John Kampfner, director of Index on Censorship, said: "The Russian government's treatment of Luke Harding is petty and vindictive, and evidence – if more was needed – of the poor state of free expression in that country."
The Foreign Office confirmed it had been in contact with its Russian counterparts, "including through a call from the foreign secretary". British officials said they were awaiting a reply.
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