UK-based "investigative" group Bellingcat claims one of the the men accused by the United Kingdom authorities of being involved in the Salisbury poisoning affair is known as Aleksandr Petrov and is a doctor working for Russian intelligence.
The British open-source website said it had identified the suspect using testimonies from people the suspect knew and a scanned copy of his passport.
Last month Bellingcat said it had identified the first suspect, originally identified under the name Ruslan Boshirov, as Anatoliy Chepiga and obtained leaked files that show Chepiga was deployed to Chechnya three times and included old passport photos of his, which resemble the man British authorities named as Boshirov.
Bellingcat said Chepiga was decorated in 2014 with the nation's top award in a secret ceremony at the Kremlin.
Bellingcat named him as Alexander Yevgenyevich Mishkin, 39, who was charged by Britain last month under the name of Alexander Petrov.
The website claims Mishkin traveled from Russian Federation to Salisbury, England, using Alexander Petrov as an alias.
It said that Mishkin was born in 1979 in the Archangelsk region in Northern European Russia and was trained as a military doctor for the Russian naval armed forces at one of Russia's elite military medical schools.
A second suspect in the poisoning of an ex-Russian spy and his daughter has been named by a British investigative website.
But investigative journalism site Bellingcat has dug into the backgrounds of "Petrov" and "Boshirov", and says it has identified both men's true identities and that they work for the GRU.
The home of former Russian spy Sergei Skripal on Christie Miller Rd in Salisbury, Wiltshire under police guard.
London's Metropolitan Police declined to comment on "speculation regarding their identities", BBC News reports. They said they went to the city to visit its cathedral.
Russian President Vladimir Putin, whose government has long denied having any knowledge of the attack, initially claimed that the two men's names "mean nothing to us", then said that they were civilians.
Following the poisoning, both Sergei Skripal and his daughter Yulia spent several weeks in a hospital, but both ultimately survived.
Anatoliy Chepiga AKA Ruslan Boshirov and Alexander Mishkin AKA Alexander Petrov.
It claims he was recruited by Russian intelligence in 2010.
In its previous reporting, the team already produced evidence that "Alexander Petrov" is not an authentic persona, but an undercover alias for an officer of a Russian security agency.