The identity of the second suspect in the Salisbury poisoning has been revealed as Dr Alexander Yevgenyevich Mishkin, a doctor in Russia’s military intelligence agency.
The Bellingcat investigative website posted the name online almost a fortnight after it outed the first suspect as Colonel Anatoliy Chepiga, 39, also a GRU officer.
British police last month accused the two men of attempting to assassinate Sergei Skripal, a former Russian double agent, and his daughter Yulia with a novichok nerve agent in Salisbury.
Prime Minister Theresa May has said the attack was “almost certainly” approved at a senior level of the Kremlin, though she has stopped short of directly accusing Russian President Vladimir Putin.
The Kremlin has denied any involvement in the attack and previously dismissed photos linking Chepiga to the GRU.
Reacting to the news, Ukrainian vice prime minister Ivanna Klympush-Tsintsadze told Sky News: “We have been clearly standing on the line of this attack, of Russian federation against the western world and we have been holding this attack by our efforts on our territory.
“By a very painful experience of our people, having lost more than 10,000 people from this aggression, we have been trying to tell the rest of the world that the threat is imminent and it’s spreading much wider.
“We are sorry to learn that the painful experience has found its way to Britain, this is yet another confirmation of the formats of Russian aggravation against other countries, it’s taking different ways and that’s what’s happened in Salisbury.”
She said they never believed the Russian story that the two men had been tourists in the country to see the town’s cathedral.
The botched hit job has plunged relations between London and Moscow to a post-Cold War low.
Mrs May has pledged to fight back by exposing the subversive activities of Russia’s military intelligence agency, the GRU.
This led to an unprecedented announcement last week by Britain and the Netherlands that a group of four GRU officers attempted to hack the intentional chemical weapons watchdog.
The Metropolitan Police released CCTV images of the two Skripal suspects in Salisbury on 4 March, the day of the botched hit and said they travelled to the UK using aliases.
Dr Mishkin used the cover of Alexander Petrov, while Anatoliy Chepiga had the bogus identity of Ruslan Boshirov.
Representatives from Bellingcat identified both men in a piece of work together with The Insider, a Russian investigative outlet.
A spokesman for the Home Office said: “We are not commenting as this is still a police investigation.”
It comes as Hillary Clinton told an audience in Oxford University on Monday that democracy is “under siege” because of Russian alleged interference in elections.
She said: “I don’t understand why the press, the political establishment and the public are so reluctant to call out what the Russians have been doing.
“What they did in Brexit, what they did in the United States.”
She added: “Democracy is under siege, international cooperation is being diminished and dismissed, and we have to ask ourselves, how do we maintain the democratic experiment in self government and how do we find the cooperation around the world and stand against this tide that seems to be sweeping Europe and the United States that is really undermining the extraordinary work that was done.”