It has been confirmed that a second police officer was contaminated by Novichok in Salisbury in March 2018.
The officer, from Wiltshire Police, was involved in the response to the poisoning of former Russian spy Sergei Skripal and his daughter Yulia.
Counter terrorism officers have confirmed traces of the nerve agent were found in his blood.
He was given treatment at the time after exposure to a very small amount of the nerve agent and returned to duties shortly afterwards.
Dawn Sturgess and Charlie Rowley were also exposed to high levels of Novichok in June 2018.
Dawn died some days later, while Charlie became critically ill.
Two men known as ‘Alexander Petrov’ and ‘Ruslan Boshirov’ are wanted by UK police after the Crown Prosecution Service authorised charges against the pair, linked to the attack on Sergei and Yulia Skripal and Detective Sergeant Nick Bailey.
Police believe they were using aliases and a European Arrest Warrant and Interpol Red Notices remain in circulation for the two men.
The Chief Medical Officer has reiterated that anyone who may have been exposed to short-term or one-off contact with low levels of Novichok and who has not suffered an obvious illness, is not at risk of any long-term health problems.
Public health experts have also confirmed that there is no change to the overall public health risk, which remains low.
However, should anyone have any concerns, then they can contact the NHS by calling 111.