"Of course, it is impossible. It is impossible to understand something like this based on the Federal Migration Service's database," Zubov said.
Last week, Bellingcat and The Insider reported that their joint investigation confirmed, through uncovered passport data, that the two Russian nationals were linked to Russian security services. Such an assumption was explained by the fact that the men's internal passports under these names were issued in 2009, while no records allegedly exist for these two individuals prior to this year.
READ MORE: Skripal Poisoning 'Suspects' Have Nothing to Do With Putin — Kremlin
Earlier, British officials charged Alexander Petrov and Ruslan Boshirov with carrying out a failed nerve agent attack on former Russian intelligence agent Sergei Skripal and his daughter Yulia in Salisbury in early March.
The Russian Foreign Ministry dismissed the charges and said that the names and photos of the suspects didn't prove that they had links to Russian military intelligence agencies.
