A POLICE officer is being tested at a Salisbury hospital for possible exposure to the deadly nerve agent Novichok.

The officer is being treated only a short distance from where Dawn Sturgess and her partner Charlie Rowley fell ill last Saturday.

They remain critically ill after handling an item that exposed them to the highly toxic nerve agent.

It is not known how the police officer came in contact with the toxin but there is not believed to be any wider risk posed to the hospital.

British forensic investigators are continuing to search for the source of the lethal nerve agent that poisoned Ms Sturgess and Mr Rowley who were exposed to the same chemical weapon used in the March attack on a Russian ex-spy and his daughter.

Sergei and Yulia Skripal were poisoned in southwest England not far from where Sturgess and Rowley live.

Police have said they are looking for a vial that may contain Novichok, a nerve agent made in the Soviet Union during the Cold War.

Officials have said the search underway Saturday could take weeks or months. It has brought more than 100 officers to Salisbury and Amesbury as suspect sites are condoned off to protect the public.