Flight details obtained by an independent and respected Russian website show Fedotov arriving in the UK on March 2 on a different flight but on the same day as two hitmen - now named as Anatoliy Chepiga and Alexander Mishkin, both revealed as highly decorated and senior members of the GRU, Russia’s military intelligence unit. Fedotov then left the UK on March 4 on the same flight as Chepiga and Mishkin.
The Telegraph understands that the Metropolitan Police, which is investigating the nerve agent attack in the Wiltshire city, is reviewing evidence with a view to considering whether or not to bring charges against Fedotov.
Chepiga and Mishkin - under their aliases Ruslan Boshirov and Alexander Petrov - have already been charged in absentia with the attack.
One source suggested that Fedotov may have been in the UK to oversee the operation. It is thought he may have travelled to Salisbury as look out on the day of the assassination attempt, making sure Col Skripal and his daughter Yulia were out of the house before Chepiga and Mishkin, a military doctor, smeared his front door handle with novichok nerve agent.
The investigation into Fedotov is hugely sensitive and Scotland Yard has declined to comment on it.
Police have released CCTV footage showing Chepiga and Mishkin in Salisbury on the day of the attack and the day before it. It is not clear if footage exists of Fedotov in the city at the same time although there will be images of him coming into the country and leaving via Heathrow airport.
As reported, Russian ex-spy Sergei Skripal, 67, and daughter Yulia Skripal, 34, were hospitalized in critical condition after they were found unconscious on a bench in the Wiltshire city on March 4 but both have recovered after weeks in the hospital. The UK government says they were poisoned with a nerve agent of a type developed by Russia called Novichok and PM Theresa May said she believed Moscow was "culpable."
A couple who authorities said found the perfume bottle after it was discarded by the attackers fared worse: Charlie Rowley recovered after treatment in the hospital but his partner, Dawn Sturgess, 44, died on July 8.
In an interview to the state-funded RT, Alexander Petrov and Ruslan Boshirov, the two Russians charged with perpetrating nerve agent attack in British Salisbury have claimed they were visiting the town's "famous" cathedral as tourists.
Petrov and Boshirov have been charged with attempting to murder of former Russian spy Sergei Skripaland his daughter Yulia in Salisbury in March by spraying Novichok nerve agent on the handle of their door. Scotland Yard have said these names are probably aliases.
A UK government spokesman rubbished the men's claims as "obfuscation and lies", while John Glen, the Conservative MP for Salisbury and South Wiltshire, called the statements "not credible".
Russian President Vladimir Putin said Russia knew the real identity of two men accused by British prosecutors of trying to murder Skripals and that they were civilians with nothing criminal about them.
Russia adamantly denies involvement in the poisoning, which had added to severe strains in ties between Russia and the West.
Putin's declaration came seven days after British authorities announced that they had charged two Russian men, identified as Aleksandr Petrov and Ruslan Boshirov, with carrying out the poisioning on March 4.
They accused the pair of smuggling the Soviet-designed nerve agent Novichok into Britain in a fake perfume flask and smearing some of the substance on the front door of Sergei Skripal's home in the English city of Salisbury, where the former GRU officer settled after being sent to the West in a Cold War-style spy swap in 2010.