British police officers
Police officers walk through the city centre, near where former Russian intelligence officer Sergei Skripal and his daughter Yulia were found poisoned, in Salisbury, BritainREUTERS/Hannah McKay

British police have identified several Russians who are suspected to have played a key role in the nerve agent attack on former double agent Sergei Skripal and his daughter, the Press Association reported on Thursday, July 19, citing a source close to the investigation.

Skripal, a former colonel in Russian military intelligence who betrayed dozens of agents to Britain's MI6 foreign spy service, and his daughter Yulia, were found unconscious on a public bench in England's Salisbury on March 4.

Britain blamed Russia for the deaths and identified the poison as Novichok, a deadly group of nerve agents developed by the Soviet military in the 1970s and 1980s. Russia has repeatedly denied any involvement in the attack.

After analysing closed-circuit television cameras, the cops suspect the involvement of several Russians in the attack on the Skripals, who spent weeks in a hospital before being spirited to a secret location, Press Association reported.

russian agent
The forensic tent, covering the bench where Sergei Skripal and his daughter Yulia were found, is repositioned by officials in protective suits in the centre of Salisbury, Britain, March 8, 2018Reuters

"Investigators believe they have identified the suspected perpetrators of the Novichok attack," the unidentified source close to the investigation said, according to PA.

"They (the investigators) are sure they (the suspects) are Russian," said the source, adding security camera images had been cross-checked with records of people who entered the country. A police spokesman declined to comment on the report.

After the attack on the Skripals, allies in Europe and the United States sided with Britain's view of the attack and ordered the biggest expulsion of Russian diplomats since the height of the Cold War. Russia retaliated by expelling Western diplomats. Moscow has repeatedly denied any involvement and accused the British intelligence agencies of staging the attack to stoke anti-Russian hysteria.

A British woman, Dawn Sturgess, died earlier this month after coming across a small bottle containing Novichok near the city of Salisbury where the Skripals were found dead. Her partner, Charlie Rowley, is still in the hospital.

A British police officer was also injured by Novichok while attending to the Skripals in March.