A woman has told how she and her husband fell ill at a Salisbury restaurant, sparking fears they had fallen victim to Novichok poisoning.
Witnesses described a scene like "armageddon" as police and emergency services, some wearing protective suits, rushed to the scene on Sunday evening as a major incident was declared.
Russian-born Anna Shapiro, 30, said she had been dining at the Prezzo Italian restaurant with partner Alex King, 42, when he began to feel unwell towards the end of the meal.
Speaking to The Sun, the model said her husband went to the toilet and she grew concerned when he did not return after 15 minutes.
"I headed up and saw him lying on the floor near the sinks," she said.
"I ran downstairs for help. I was panicked."
Soon after when Ms Shapiro went to raise the alarm, she too began to feel unwell, the paper said.
Emergency services were called to the city centre restaurant at 6.45pm and the pair were taken to Salisbury District Hospital.
Wiltshire Police said inquiries were ongoing into what caused them to become unwell, although they have ruled out exposure to Novichok or a similar poison.
"Tests have confirmed that the two patients who fell ill in Prezzo restaurant in Salisbury on Sunday evening were not exposed to any kind of nerve agent," the force said.
The incident came amid heightened tensions in Salisbury in the wake of the poisoning of former Russian spy Sergei Skripal and his daughter, Yulia, in March.
The Prezzo is a short walk from Queen Elizabeth Gardens, which was until recently closed off after 44-year-old Dawn Sturgess was fatally poisoned by the nerve agent in June.
Amanda Worne was at the restaurant when the drama began on Sunday.
She described how a "beautiful blonde" had gone up to the restaurant's toilet before returning "hysterical".
"(She said) 'Oh my God, we need an ambulance, we need an ambulance, someone help we need an ambulance'," Ms Worne told the Press Association.
Paramedics arrived and donned protective clothing after discovering the two patients.
"The next thing it was all carnage, it was armageddon, there were sirens, ambulances," she said.
A Prezzo spokesman said: "We have been informed that Wiltshire police are not linking the event on Sunday evening to the recent nerve agent poisonings in Salisbury and Amesbury and have made no suggestion that the illness was a result of anything present in our restaurant.
"Based on the information we have received, this is an isolated incident. We can also confirm that none of our team suffered any related illness, and all are well and keen to return to duty when the restaurant re-opens.
"They dealt with the circumstances of Sunday evening in an admirable manner and our thanks go to each of them."
The Salisbury branch remains closed "as a precautionary measure" while police complete tests into the cause of the illness, the spokesman added.