Britain’s national security adviser, Mark Sedwill, claimed Russian intelligence had been spying on former double agent Sergei Skripal and his daughter Yulia for at least five years prior to the nerve agent attack in March in a letter to NATO.
Mr Sedwill submitted the letter to NATO Secretary General Jens Stoltenberg on Friday, including the claim that Russia’s GRU military intelligence service had targeted the email accounts of Yulia in 2013.
Mr Sedwill also said in the letter that Russia had tested methods to use chemical agents, “including application to door handles”, and that “the Russian intelligence services view at least some of its defectors as legitimate targets for assassination.”
The Skripals were the target of a nerve agent attack in March that left both of them hospitalised for weeks, only recently starting to recover.
London has put the blame for the attack on Moscow, claiming the chemical agent used was one developed by the Soviet Union.
A report by the Organisation for the Prohibition of Chemical Weapons this week confirmed the chemical composition and name of the nerve agent as Novichok.
Russian Foreign Minister Sergei Lavrov said that while the report confirmed the substance, said it did not say where the substance originated.
In a separate statement Russia’s British ambassador, Alexander Yakovenko also accused the British government of trying to destroy and classify evidence in the case.
“We get the impression that the British government is deliberately pursuing the policy of destroying all possible evidence, classifying all remaining materials and making an independent and transparent investigation impossible,” Mr Yakovenko said.