LONDON (AFP) - A couple who fell ill in the British city of Salisbury at the weekend had not been in contact with the nerve agent used to poison a Russian ex-spy and his daughter, police said on Tuesday (Sept 18), confirming there was no link between the incidents.

Parts of the city in south-west England were sealed off and a hazardous area response team called to the scene after the pair became unwell at an Italian restaurant on Sunday evening.

The incident sparked fears that their illness was caused by traces of the Novichok chemical that poisoned Sergei Skripal and his daughter Yulia in Salisbury in March.

The local police department said the pair who got sick on Sunday were tested for traces of the deadly nerve agent in light of "recent events in the south of the country".

"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 local police department said.

The police statement said tests on the two - identified only as 42-year-old man and a 30-year-old woman - were still ongoing.

A British couple named Dawn Sturgess and Charlie Rowley came into contact with the same nerve agent near Salisbury at the end of June.

Sturgess died on July 8 and police launched a murder probe.

Britain suspects two men linked to Russia's military intelligence service of poisoning Skripal on Kremlin orders in retribution for his work with Western intelligence agencies.

Skripal is believed to have identified the names of active Russian spies to European governments.

Both he and Yulia survived the attack.

Russia denies involvement and the two suspects gave a bizarre interview to a Kremlin-backed TV channel Thursday in which they claimed to have visited Salisbury twice around the time of Skripal's poisoning for tourism.