"The possibility that the two investigations might be linked is clearly a key line of inquiry for police. However, Assistant Commissioner Neil Basu stressed on Wednesday, 4 July, the importance of the investigation being led by the evidence available and the facts alone," the Metropolitan Police said in a statement.
According to the British police, the pair was exposed to the nerve agent after a contact with a contaminated item.
"Following further tests of samples from the patients, we now know that they [the Amesbury victims] were exposed to the nerve agent after handling a contaminated item… We are not in a position to say whether the nerve agent was from the same batch that the Skripals were exposed to," the statement said.
Both Amesbury and Salisbury are located close to the military's Porton-Down laboratory, which conducted the the research in both cases.
Addressing the Amesbury incident, UK Home Secretary Sajid Javid said that Britain would take "further action" if Russia's involvement in the incident confirmed, despite the fact there were no proof that Moscow was somehow involved in this case as well. The official noted later that the authorities "don't want to jump to conclusions."
Russia has repeatedly refuted all the allegations of the involvement in nerve agent attack and offered UK its assistance in the Skripal case investigation. The incident, however, led to a diplomatic clash between two countries last spring. Both Skripals have since been discharged from the hospital and their current whereabouts and condition are unknown.