A police officer tested for possible exposure to a nerve agent in Salisbury has been given the medical all-clear.
The Wiltshire Police officer was treated a short distance from Amesbury where Dawn Sturgess, 44, and her partner Charlie Rowley, 45, fell ill last Saturday.
They remain in a critical condition after being exposed to Novichok by handling a contaminated item.
The officer was cleared at Salisbury District Hospital.
Wiltshire Police confirmed that one of their officers had been "seeking medical advice" at the hospital as part of "a precautionary measure".
A Salisbury District Hospital spokesperson said: "There is nothing to suggest there is any wider risk to anyone at the hospital."
The spokesperson added that the hospital had "the ability to carry out the appropriate specialist tests.
"Salisbury District Hospital has seen a number of members of the public who have come to the hospital with health concerns since this incident started and none have required any treatment.
"We would like to reiterate the advice from Public Health England (PHE) that the risk to the wider public remains low."
The emergency department at the Great Western Hospital in Swindon where the officer initially attended had been closed but reopened at about 22:00 BST.
An operation into the poisoning of Mr Rowley and Ms Sturgess is expected to take months as police examine more than 1,300 hours of CCTV footage.
Police are conducting a search for the item believed to have exposed the pair to Novichok.
However, BBC security correspondent Frank Gardner says the hunt has been hindered by the heatwave as chemical weapons experts wearing Hazmat (Hazardous Material) suits can only spend a few minutes inside the property being searched.
Locations visited by the couple, as identified by the police, include Muggleton Road, Boots pharmacy and the Baptist church in Amesbury; John Baker House and Queen Elizabeth Gardens in Salisbury.
PHE issued "highly precautionary advice" for anyone who visited those locations to wash worn clothes with a regular detergent at normal temperature and wipe items like phones and handbags.
This investigation comes months after the poisoning of ex-Russian spy Sergei Skripal and his daughter Yulia.
Home Secretary Sajid Javid said the "strong working assumption" was that the pair came into contact with Novichok in a location which had not been cleaned up following the Skripal poisoning.
He called on Russia to explain "exactly what has gone on" and accused the country of using Britain as a "dumping ground for poison".
The Russian Embassy accused the UK of trying to "frighten its own citizens".