Investigators will use “classic detective work” as well as consulting with medical experts as they try to find out how two Russians were apparently poisoned on UK soil.
Bob Broadhurst, a former Metropolitan Police Commander who dealt with public safety issues after Alexander Litvinenko was poisoned with polonium in London in 2006, said Wiltshire Police will be working closely with health advisers.
The force is currently investigating how former Russian spy Sergei Skripal and his daughter were left fighting for their lives after falling ill in Salisbury on Sunday.
Mr Broadhurst said: “It is the same as in Litvinenko, you work your way back from a start point.
“What do we know about this man and his daughter, who has met with him recently, telephone stuff, all the usual investigative bits.”
“If you then go back to classic detective work tracing his movements and if they identify someone as the assassin if you like, the perpetrator, their movements as well.
“That was what we did with the polonium, went back to where these people had been, put a scanner over it and lo and behold there was a trace.”
In the Litvinenko investigation, traces of the radioactive substance were found in more than 50 locations.
It was only after he died that polonium was confirmed as the poison, something that would only have been available to Russian assassins.
Mr Broadhurst added: “It overlaps in terms of public safety between the investigative police world and the forensic medical world.
“What was the cause of this illness?
“Was it a poison, and if so how did he ingest it? Who else is potentially at risk?
“You will have almost a parallel investigation – detectives and doctors trying to find cause and effect.”