A British journalist has been expelled from Russia in an apparent response to the reporting of WikiLeaks cables unfavourable to Vladimir Putin's rule.
Luke Harding, the Guardian's Moscow correspondent, was detained at the city's airport for 45 minutes while attempting to re-enter the country over the weekend.
He was put on a flight back to the UK by border guards who reportedly told him: "For you, Russia is closed."
Foreign Secretary William Hague has phoned Moscow in a bid to shed light on the removal of Harding. The Foreign Office said it was still "awaiting a reply".
The journalist was returning from London where he had been working on the WikiLeaks cables when he was stopped in the airport. His visa was annulled and his passport only handed back to him once he was on a plane heading back to London.
In a tweet, Harding suggested that his work on the leaked cables and their damning assessment of Russia under Mr Putin's rule might be behind his expulsion. he wrote: "The Russians have been unhappy with my reporting for a while. But it seems WikiLeaks may have been the final straw."
In another post he wrote: "Extremely sad to leave Russia under these circumstances. My visa valid until end of May."
As part of a series of WikiLeaks articles, he reported on allegations contained in US diplomatic cables that suggested that Russia had become a "virtual mafia state" under former president, now prime minister Putin.
The expulsion of Harding is thought to be the first such removal of a British journalist since 1989, when Angus Roxburgh, then of The Sunday Times, was kicked out as part of tit-for-tat expulsions in which 11 Russian spies were told to leave London.
A spokeswoman from the Foreign Office said: "We have been in contact with the Russian Ministry of Foreign Affairs, including through a call from the Foreign Secretary, to seek clarity on this decision. We are awaiting a reply."