SWINDON’S accident and emergency department was sealed off for five hours after a nerve agent poison scare.

It came 24 hours before Novichok claimed its first victim, 44-year-old Durrington mum Dawn Sturgess.

On Saturday, security staff at the Great Western Hospital told members of the public to try hospitals in Cirencester and Bath as emergency ambulances were diverted to other towns. Patients inside the hospital described the A&E as being placed on lockdown.

The authorities feared a police officer who attended GWH may have been displaying signs of nerve agent poisoning.

Patients outside the hospital spoke of the A&E as being “in total lockdown”. One woman, 72, said: “No one is going in, no one is going out. All the ambulances are being diverted elsewhere.”

Another woman, 68, who was with her husband in the Urgent Treatment Centre, said: “They wouldn’t let us go, because of this incident that we were told was something to do with contamination.”

The scare came after a Wiltshire Police officer sought medical attention in connection with the ongoing incident in Amesbury.

A couple in their 40s, who were found collapsed in the town, remain in hospital after being poisoned with Novichok.

After reporting at GWH, the officer was rushed to Salisbury District Hospital, but was later given the all-clear.

An NHS spokesman said at around 9pm on Saturday: “There is nothing to suggest there is any wider risk to anyone at the [Great Western] hospital.”

Further tests at Salisbury hospital revealed the officer had not been targeted with the deadly nerve agent and Wiltshire Police announced shortly before 11pm their officer had been given the all-clear by doctors.

A spokesman for the force said: “We are pleased to confirm that the police officer who sought precautionary medical advice at Salisbury District Hospital in connection with the ongoing incident in Amesbury has been assessed and given the all-clear.

“We would like to reiterate the advice from Public Health England that the risk to the public remains low.”

GWH said the A&E department had been sealed off as a precautionary measure, with staff following guidance from Public Health England.

An individual, believed to be a member of staff, dressed in a green plastic hazardous materials suit, could be seen emerging from a rear entrance to the A&E at around 8.10pm. Within 10 minutes, two police cars rushed into the A&E forecourt to collect bags left behind screens just outside the department doors.

Robert Buckland, South Swindon MP, said: “Our emergency services at GWH have once again responded brilliantly. I very much hope the officer will recover swiftly.”

A&E reopened at 10.10pm. The rest of the hospital was unaffected.

Dawn Sturgess, 44, from Durrington, died at Salisbury District Hospital earlier this evening, the Metropolitan Police said. She was originally admitted to hospital on Saturday, June 30, after falling ill in Amesbury, 30 miles from Swindon.

Detectives working to establish how Ms Sturgess and partner Charlie Rowley came into contact with deadly nerve agent Novichok have now launched a murder enquiry.