“Many lethal doses” of the nerve agent novichok were likely applied to Sergei Skripal’s door handle in Salisbury, an inquiry into the 2018 poisonings has heard.
The lead scientific adviser to police investigating the attack, known only by the codename MK26, told the Dawn Sturgess Inquiry that a sample the size of “a third to a sixth of a grain of salt” of novichok could have been a fatal dose for a human.
Former spy Mr Skripal, his daughter Yulia and former police officer Nick Bailey were all poisoned by the chemical in the Wiltshire city in March 2018.
Ms Sturgess, 44, died on 8 July of that year after she was exposed to the nerve agent, which had been left in a discarded perfume bottle in nearby Amesbury. Ms Sturgess’s partner Charlie Rowley was also poisoned but survived.
The witness from the Defence Science and Technology Laboratory (DSTL) said very few people would have been capable of producing the novichok used in the attack safely because it is “highly hazardous in small quantities”.
MK26, who has worked as a research scientist for 20 years, added the “competence of the scientists working with [the novichok] would need to be extremely advanced”.
The witness said samples of the nerve agent were taken from Mr Skripal’s door handle 12 days after the poisonings, with rainwater and snow potentially affecting its concentration levels.
They told the inquiry: “After many days of weathering, with the contamination found throughout the locations visited in Salisbury that afternoon by the Skripals, suggests that it is highly likely that there were many lethal doses of the highly toxic specific novichok applied to the door handle.”
The nerve agent had a concentration level of 97 to 98%, the witness said.
During the inquiry, the witness said Russian President Vladimir Putin was “incorrect” to say coming into contact with novichok would result in someone “dying on the spot”, in a diplomatic telegram in March 2018.
MK26 also said it was “not possible to exclude that there were two bottles”, when quizzed on whether they were able to say in an expert capacity that the bottle found in Amesbury was also used for the Salisbury attack.
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Following the poisonings, an international arrest warrant was issued for the two alleged attempted assassins, along with a third alleged accomplice.
However, Russia does not allow the extradition of its citizens, and it is thought to be unlikely that the trio will ever stand trial.
Mr Skripal served as a member of Russian military intelligence, the GRU, but was convicted in Russia on espionage charges in 2004 after allegedly spying for Britain, the inquiry previously heard.
He was sentenced to 13 years in prison, but in 2010 he was given a presidential pardon and brought to the UK on a prisoner exchange before settling in Salisbury.
The Skripals will not give evidence at the inquiry due to safety concerns.
The inquiry continues.
