Novichok nerve agent that killed UK woman could remain active for 50 years

The nerve agent that killed a British woman could be active for 50 years if it remains in a container, Britain’s top counterterrorism officer has said.

Neil Basu told a packed public meeting in Amesbury that no forensic link had been established between the novichok that poisoned Dawn Sturgess and Charlie Rowley, and that which led to the collapse of former Russian spy Sergei Skripal and his daughter, Yulia – and it was possible a scientific link is never established.

But Basu, an assistant commissioner with the Metropolitan police who leads the police counterterrorism network, said it was implausible there was no connection between the two incidents.

He said it was possible the pair had picked up a container of novichok at the time of the Skripal attack in March but had only now opened it. He accepted there could even be several containers of novichok – but it was impossible to know.

Basu also said for the first time that a “particular” area of Queen Elizabeth Gardens in Salisbury, rather than the whole park, was a focus. He said it would be several more weeks, if not months, before the investigation was over.