The Kremlin today said it would be "absurd" to suggest Russia was involved in the death of a British woman exposed to the Novichok nerve agent.
"We don't know that Russia has been mentioned or associated with this," President Vladimir Putin's spokesman Dmitry Peskov said.
"We consider that in any case it would be quite absurd."
Peskov added that "we of course very much regret the death of the British citizen."