"The Russian side has no information about this mysterious character, no one from our embassy in Rome has 'run away'," she said.
According to Zakharova, UK media have reported on a Russian defector, a former employee of the Russian Embassy in Rome, who was allegedly recruited by UK intelligence, code-named Apollo, and who allegedly provided the real names of the poisoners of Skripals.
Last week, 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 Metropolitan Police released images of the suspected perpetrators, claiming that they were Russian military intelligence officers.
The police suggested that the two suspects, who allegedly traveled on valid Russian passports, arrived in London from Moscow two days before the alleged assassination attempt.
London police also published a photo of what is believed to be a box of perfume with the Novichok nerve agent, which the two alleged perpetrators ostensibly smeared on the Skripal's front door.
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.