UK has not yet identified a suspect in the poisoning of ex-Russian spy Sergei Skripal investigation

No suspects have been identified in the investigation surrounding the poisoning of ex-spy Sergei Skripal.

The former Russian double agent and his daughter Yulia were found slumped on a bench in the southern English city of Salisbury on March 4 after a liquid form the Novichok type of nerve agent was applied to the front door of his home.

Britain has pointed the finger at Russia, although investigations are yet to identify any suspects.

When asked by MPs on the British parliament’s defence committee if the suspects behind the poisoning had been identified, Mark Sedwill, national security adviser to Prime Minister Theresa May, said: “Not yet”.

Moscow has denied involvement in the nerve agent attack and the fallout which followed the incident led to the biggest Western expulsions of Russian diplomats since the Cold War.

The UK is stepping up protection for other defectors, like Skripal, who might also be at risk, Sedwill confirmed on Tuesday.

The attack left both Skripal and his daughter critically ill in hospital for weeks. A British policeman was also treated in hospital.

Yulia, 33, was discharged last month but her father, a former colonel in Russian military intelligence who betrayed dozens of agents to Britain’s MI6 foreign spy service, remains in hospital.

Other Russian dissidents and defectors have also died in the UK in recent years, surrounded by suspicious circumstances.

A murder investigation was launched following the death of Russian businessman Nikolai Glushkov, who was found dead at his London home days after Skripal was poisoned.

However, detectives said there was nothing to link the two events.

Following the Skripals’ poisoning, police and intelligence services were also instructed to look into 14 other deaths which had not originally been treated as suspicious, but where allegations of Russian state involvement had been made.

In a letter to NATO Secretary General Jens Stoltenberg last month, Sedwill said Russia’s intelligence agencies spied Skripal and his daughter for at least five years and regarded some defectors as “legitimate targets for assassination”.

Sedwill told the British lawmakers that preventative steps were now being taken.

“The police who are responsible for protective security and the various agencies alongside them are reviewing the security of all people who might be vulnerable in that way,” Sedwill informed the committee.