Russia said on Monday that it had ordered a British diplomat to leave the country after discovering signs of espionage, Russian media quoted the Federal Security Service as saying.
The FSB, the main successor to the Soviet-era KGB, said that the second secretary at the Moscow embassy had been ordered to leave within two weeks after FSB counter-intelligence officers revealed the "undeclared intelligence presence.”
The FSB said that it had found signs that the diplomat was "carrying out intelligence and subversive activities that threaten the security of the Russian Federation," Russian media reported.
In particular, the FSB said, the diplomat had tried to obtain sensitive information about the Russian economy during informal meetings.
The British embassy made no immediate public comment.
Relations between London and Moscow, currently at a low point over the Ukraine war, have been strained by spying allegations for decades.
In 2006, former FSB officer and Russian defector Alexander Litvinenko was killed in London, poisoned by polonium in what British investigators said was a hit by the Russian secret service.
In 2018, the UK said Russian double agent Sergei Skripal was poisoned with a Novichok nerve agent in the British cathedral city of Salisbury.
One member of the public was killed after handling the delivery device, a discarded perfume bottle, triggering the largest Western expulsion of Russian diplomats alleged to be spies in decades.
