Former double agent Sergei Skripal and his daughter Yulia fell into comas after coming into contact with a banned chemical called Novichok in March 2018.
They both survived but a local resident named Dawn Sturgess died after coming into contact with a perfume bottle UK police believe was used to transport it from Russia.
The UK government is seeking the extradition of two suspected members of Russia’s military intelligence service that London believes carried out the attack on Kremlin orders.
Moscow denies its involvement.
Detectives from Britain’s Counter Terrorism Policing (CTP) network said “traces of the nerve agent” were found in blood samples taken from a second police officer who showed signs of exposure at the time.
It said the dose was “very small” and the officer, who has requested anonymity, “continues to receive support” from the Salisbury police.
Detective sergeant Nick Bailey has recovered after receiving a larger dose of Novichok.
“The investigation remains ongoing, and there are parts of the picture that we are continuing to piece together,” the CTP said.
“In particular, we are keen to hear from anyone who may have seen the counterfeit ‘Nina Ricci’ perfume box or bottle” between the day of the Skripal poisoning and the day Sturgess’s friend Charlie Rowley picked it up in a park in June. (AFP)