A hospital spokesman said: "The police officer who was transferred to Salisbury District Hospital this evening has been tested and does not require any treatment".
The British couple who mysteriously fell ill over the weekend tested positive for Novichok - the same poison that nearly killed a Russian spy and his daughter who lived just a few miles away, police said Sunday.
A local policeman, Detective Sergeant Nick Bailey, fell seriously ill in that incident but later recovered, along with the Skripals.
Police said there was no evidence that Ms Sturgess and Mr Rowley visited any of the sites that were decontaminated following the attempted murders of Sergei and Yulia Skripal.
Police declared a major incident on Wednesday after Sturgess and then Rowley collapsed last Saturday.
The Conservative Council Leader of Salisbury described the man and woman exposed to Novichok as having a "chequered history with housing", as counter terrorism police lead the investigation.
A police officer is in hospital in the United Kingdom amid concerns of possible exposure to the Novichok nerve agent.
The officer, believed to be with Wiltshire Police, is being treated at Salisbury District Hospital after first attending Great Western Hospital in Swindon.More news: Iran summons French, Belgium, German envoys over diplomat arrest
Mr Rowley's residence, where the couple fell ill, also had a heavy operational presence. Skripal was discharged from the hospital in May and his daughter was released in April.
Salisbury District Hospital is now treating an Amesbury couple who British investigators believe has been infected by Novichok, a Soviet-developed compound from a group of nerve agents. They are said to be in critical condition.
"We would like to reiterate the advice from Public Health England that the risk to the wider public remains low", it said.
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.
"Due to the unique challenges involved with this operation, police activity is expected to take weeks and months to complete", said London's Metropolitan Police in a statement.
But Russia quickly hit back, denouncing Britain for playing "dirty political games", trying to "muddy the waters" and "frighten its own citizens".
Police said they had been exposed to a nerve agent.
"The priority for the investigation team now is to establish how these two people have come into contact with this nerve agent", Basu said.
The poisoning of the Skripals, who were found slumped over on a park bench in Salisbury, sparked a minor global incident, with the United Kingdom blaming Russian Federation and Moscow denying all responsibility.